Effective Date: 1 August 2026
These terms and conditions (“Terms & Conditions”) constitute a legally binding agreement between you, whether personally or on behalf of an entity ("User", "you" or "your"), and MASVERSE EDUTECH SDN BHD (Registration No. 202301015731 (1509653-K)), its holding company, subsidiaries and/or any affiliate company (collectively, the "Company", "we", "us" or "our"), as owner and operator of BlockchainCert.my and the related website, software application and digital platforms operated by the Company (collectively, the "Platform").
By creating an account, purchasing or using any service made through the Platform (each a “Service”), clicking to accept this Terms & Conditions or otherwise accessing or using the Platform, you acknowledge that you have read and understood these Terms & Conditions and agree to be bound by them. You also acknowledge that personal data will be processed in accordance with the Company’s Privacy Policy and applicable law.
If you access or use the Platform on behalf of an entity, you represent and warrant that you have full authority to bind that entity to these Terms & Conditions. You are responsible for:-
(a) maintaining the confidentiality and security of your account credentials;
(b) ensuring that only persons authorised by you access or use the Platform through your account; and
(c) all acts and omissions carried out through your account, except to the extent caused by the Company’s act or omission.
Any person whom you authorise to access or use the Platform through your account must comply with these Terms & Conditions. You must notify the Company promptly if you become aware of any unauthorised access to or use of your account. If you do not agree to these Terms & Conditions, you must not create an account, purchase or use any Service, or access or use the Platform.
1.1 These Terms & Conditions govern your access to and use of the Platform, the Services and any other materials, information, software, templates or other content made available by the Company through the Platform ("Content").
1.2 Certain Services may be subject to additional terms, policies, service descriptions, order forms or other conditions presented to you before purchase or use. Those additional terms are incorporated into and form part of these Terms & Conditions.
1.3 If there is any inconsistency between these Terms & Conditions and any additional terms expressly applicable to a particular Service, the additional terms shall prevail solely in relation to that Service, unless otherwise stated.
1.4 Nothing in these Terms & Conditions excludes, restricts or modifies any right or remedy that cannot lawfully be excluded, restricted or modified under applicable law.
(a) The Company may offer different Service options through the Platform, including subscription plans, Credential Credit packages, promotional plans, memberships and other paid or unpaid services.
(b) Certain Service options may only be accessed after the applicable payment has been successfully received and confirmed by the Company or its appointed payment service provider.
(c) The features, usage limits, fees, subscription periods and other conditions applicable to each Service will be displayed on the Platform or otherwise communicated to the User before purchase.
(d) Unless expressly stated otherwise, any trial, promotional or free Service may be modified, suspended or withdrawn at any time and may be subject to additional limits.
(a) The Company shall use reasonable care and skill to keep the Services operational. However, the Services may experience temporary interruptions due to technical difficulties, maintenance, testing, security measures, updates, third-party service failures or changes required to comply with applicable law or regulatory requirements.
(b) The Company continually improve the Services and may modify, replace, suspend or discontinue all or part of a Service including particular functions, features, subscription plans or promotional offerings. Where a change materially reduces the core functionality or a paid Service during a current paid subscription period, the Company will use reasonable efforts to give prior notice and, where required by applicable law, provide an appropriate remedy.
(c) To the fullest extent permitted by applicable law, the Company is not liable for internet, telecommunications, payment-network, blockchain-network or other third-party outages or failures, or events beyond our reasonable control. This clause does not affect any non-excludable right or remedy under applicable law.
(a) The Platform may use blockchain, distributed ledger or similar technologies selected by the Company in connection with records relating to certificates and other credentials.
(b) Certain blockchain or verification records may not be capable of alteration or deletion and may remain accessible or verifiable after a credential is revoked, corrected, superseded or reissued. Where reasonably practicable, the Platform may record a hash, identifier, status or other verification reference rather than the full credential data on chain.
(c) Before issuing, uploading or publishing a credential, the User must ensure that the information is accurate and complete, provide all notices and obtain and retain all consents, authorisations and approvals required by applicable law. The User must not place sensitive personal data or unnecessary personal data directly on a blockchain or other immutable record through the Platform.
(d) Except as expressly agreed by the Company in writing and subject to applicable law, verification through the Platform confirms only that the information presented corresponds with the record maintained or referenced by the Platform and the credential status shown at the time of verification. The Company does not independently verify or warrant the recipient’s identity, the User’s authority to issue the credential, the credential’s accuracy or legal effect, its accreditation or regulatory recognition, or its acceptance by any third party.
(a) You may need to create an account to use all or part of a Service. Your username, password and other account credentials are for use only by you and your authorised users and must be kept confidential and secure. You are responsible for activity carried out through your account, subject to the exceptions stated in the introductory provisions of these Terms & Conditions.
(b) You must provide accurate, current and complete account information and keep it updated. If you believe that your account has been compromised, you must immediately notify the support team and take reasonable steps requested by the Company to secure the account.
(c) The Company may reclaim, suspend or require a User to change a username or account identifier where reasonably necessary to address impersonation, misleading representation, offensive content, security risks or potential infringement of intellectual property rights.
(d) An account may only be created or administered by a person who is at least eighteen (18) years of age and authorised to act for the User.
For verification, Users must submit the following information or documents:-
(a) Organisation name;
(b) Company or business address;
(c) Organisation email address;
(d) Organisation phone number;
(e) Organisation website;
(f) Organisation registration number; and
(g) Supporting document issued by the Companies Commission Malaysia (CCM) or an equivalent regulatory authority.
The Company may reject incomplete, inaccurate, misleading or fraudulent submissions and may request additional information or documentation where reasonably necessary for verification, fraud prevention, risk management or compliance with applicable law.
(a) Templates uploaded by the Users must comply with copyright, trademark and other intellectual property laws. The User retains ownership of its templates but grants the Company the license set out in Clause 5.2 solely to the extent required to provide, secure, maintain and improve the Services.
(b) The User must ensure that its templates are accurate, technically suitable and appropriate for the intended credential issuance. The Company is not responsible for error contained in User-supplied templates.
(a) Users must ensure that the registration forms created or used through the Platform comply with applicable laws. Where a registration form or credential contains personal data relating to a person below eighteen (18) years of age, the User must, before collecting, uploading, publishing or making that personal data verifiable, provide all required notices and obtain and retain all consents and authorisations required by applicable law from the person’s parent, guardian or other person having parental responsibility.
(b) Registration forms must only be used for their stated and lawful purpose, such as credential issuance or event registration, and must not collect personal data that is excessive for that purpose.
(a) The User represents and warrants that, before submitting personal data to the Platform, it has provided every required privacy notice, has a lawful basis for processing, and has obtained every consent and authority required by applicable law, including any authority required for publication or public verification through the Platform.
(b) The User must not submit sensitive personal data or personal data that is excessive for the stated purpose unless expressly approved by the Company and permitted by applicable law. The User must implement reasonable organisational and technical measures to protect personal data under its control.
(c) As between the parties, the User acts as the data controller for personal data in respect of which it determines the purposes and means of processing. To the extent that the Company processes such personal data solely on the User’s documented instructions, the Company acts as a data processor. The Company acts as an independent data controller for personal data processed for its own purposes, including account administration, KYB, billing, payments, security, fraud prevention, analytics, legal compliance and Platform administration.
(d) The Company may engage service providers and sub-processors, and may transfer personal data outside Malaysia, in each case in accordance with the Personal Data Protection Act 2010, as amended, other applicable law and the Privacy Policy.
(e) Each party must provide reasonable cooperation to the other in relation to data-subject requests, security incidents, investigations and regulatory enquiries concerning personal data processed through the Platform. The User must notify the Company without undue delay after becoming aware of any actual or suspected personal data breach affecting personal data submitted to the Platform.
(a) Credential credits are prepaid credits that may be redeemed to issue certificates or other credentials through the Platform (“Credential Credits”). Users may top up Credential Credits through the Company’s online portal. Credential Credits will be added to the User's account after successful payment confirmation.
(b) Credential Credits are tied to the User’s applicable subscription plan and expire in accordance with the validity period disclosed for that plan or package at the time of purchase. Credential Credit top ups are final and non-refundable except for duplicated payments qualifying under the Refund Policy, where the Company expressly agrees otherwise, or to the extent a refund is required by non-excludable applicable law.
(c) Credential Credits have no cash value, may not be transferred between accounts or resold, and may only be used for the Services specified by the Company, unless the applicable plan expressly states otherwise.
(a) Users may choose from the plans made available by the Company. A selected plan will be activated following payment confirmation.
(b) Unless the applicable plan or order form states otherwise, unused Credential Credits from a previous plan or subscription period will not carry forward when an upgrade, downgrade or renewal of the User’s plan takes effect. Users should use their remaining Credential Credits before the change or renewal takes effect.
(c) Unless otherwise stated at the time of purchase or required by applicable law, the Company does not apply pro-rata calculations to plan changes. The User must pay the full price of the new plan regardless of when the change occurs.
(a) Each subscription continues for the period selected at purchase.
(b) The subscription automatically renews for successive periods of the same length unless cancelled before the renewal date, and the applicable fee will be charged using the approved payment method.
(c) Cancellation takes effect at the end of the current paid period and does not entitle the User to a pro-rata refund or reimbursement for unused Credential Credits, except where these Terms & Conditions expressly provide otherwise or mandatory law requires a refund.
(d) Subject to Clause 3.7(b), any unused Credential Credits from the preceding subscription period will expire upon commencement of each renewal period and will not carry forward into that renewal period, including where the subscription renews automatically.
(a) Subject to your compliance with these Terms & Conditions and any applicable terms, the Company grants you and your authorised users limited, non-exclusive, non-transferable, non-sublicensable and revocable permission to access and use the Service and the Content solely for the purposes permitted by these Terms & Conditions and the applicable Service plan ("Access"). This Access continues until the applicable access or subscription period expires, unless earlier suspended or terminated in accordance with these Terms & Conditions.
(b) The software applications and the Content are licensed, not sold or transferred. The Company, and its licensors retain all right, title and interest in and to the software applications and the Content including all copies installed or accessed on any device.
(a) The Service, Content and materials, including but not limited to the software, source and object code, APIs, databases, workflows, interfaces, layouts, templates supplied by the Company, graphics, text, designs, documentation, trademarks, logos, domain names, compilation, arrangement and look and feel of the Platform, are owned by the Company or its licensors and are protected by applicable intellectual property laws. These Terms & Conditions do not grant the User any right to use the Company's brand features except as expressly permitted in writing.
(b) When using the Platform, you must:-
(i) keep intact all copyright, trademark and other proprietary notices;
(ii) comply with all applicable laws and the applicable Service plan;
(iii) ensure that all information and content submitted through your account is accurate, lawful and not misleading; and
(iv) use reasonable security measures to prevent unauthorised access or misuse.
(c) Except to the extent expressly permitted by applicable law that cannot be excluded by agreement, you must not, and must not permit any third party to:-
(i) sell, resell, sublicense, rent, lease, distribute, transfer or commercially exploit the Platform or Content, except through functionality expressly provided by the Company;
(ii) copy, modify, adapt, translate, reverse engineer, disassemble, decompile or attempt to discover source code, underlying ideas, algorithms or non-public APIs associated with the Platform;
(iii) bypass or interfere with security, authentication, usage limits, access controls or technical restrictions;
(iv) introduce malware, harmful code or any device, software or routine that interferes or attempts to interfere with the operation of the Platform;
(v) impose an unreasonable or disproportionately large load on the Platform’s infrastructure;
(vi) use any robot, scraper, crawler or data-mining process to extract, frame, mask, copy or distribute any portion of the Platform, except standard search-engine indexing or ordinary browser use permitted by the Company;
(vii) use the Platform for unlawful, fraudulent, deceptive, infringing, abusive or harmful activity, or to issue credentials that falsely imply accreditation, recognition, affiliation, sponsorship or endorsement; or
(viii) access or use the Platform to develop, train or benchmark a competing product or service without the Company’s prior written consent.
(a) Subscription, Credential Credits and other paid Services are subject to fees displayed on the Platform or stated in the applicable order form. Unless expressly stated otherwise, fees are quoted exclusive of applicable taxes, duties or levies, which are the User’s responsibility.
(b) Payments may be processed by the Company and or the Company’s appointed payment service provider. The User authorises the Company and the payment service provider to charge the approved payment method for all applicable fees, taxes, refunds, chargebacks and adjustments.
(c) Where a User collects payments from end users for certificates or related services through the Platform, the identity of the merchant of record must be confirmed in the applicable checkout, order form or payment-provider terms. Unless the Company is expressly identified as the seller or merchant of record, the Company provides payment facilitation functionality only and does not become the issuer, seller, guarantor or substantive supplier of the User’s certificate or related service.
(d) Subject to payment-provider settlement, fraud screening, chargebacks, refunds, reserves, legal requirements and the accuracy of the User’s bank details, payouts to Users for transactions completed in the previous month are scheduled to be processed on the fifteenth (15th) day of each month. Processing may take up to ten (10) working days. If the scheduled processing date is not a working day, processing may begin on the next working day.
(e) The Company will deduct an administrative service fee equal to the higher of: (a) three per cent (3%) of the amount remaining after deduction of payment-gateway fees; or (b) Ringgit Malaysia Three (RM3.00). The Company may change the fee structure by giving reasonable prior notice, and any change will apply prospectively.
(f) The Company may withhold, delay, reverse or set off a payout where reasonably necessary to address suspected fraud, chargebacks, refunds, disputes, sanctions, legal obligations, inaccurate payment information or amounts owed by the User to the Company.
(a) Where a User offers or sells a certificate or related service to an end user through the Platform, the User is solely responsible for the certificate or service, its description, price, tax treatment, legality, delivery, accuracy, refund obligations, consumer disclosures and after-sale support.
(b) The User must use any Platform functionality provided to enable correction of order errors, acknowledge each order without undue delay, maintain an accessible complaint channel, address complaints promptly, and retain transaction, order and advertising for at least the minimum period required by applicable law.
(c) The Company may prevent, delay or suspend a transaction until the required information is complete, and may review, restrict or remove any advertisement, credential or listing that appears unlawful, inaccurate, misleading or non-compliant. A complaint channel is available at support@masverse.com.my.
(d) Except where the Company is expressly identified as the seller or merchant of record, the Company does not assume responsibility for the User, the certificate, the related service or the underlying transaction merely by providing payment, order, complaint, verification or review functionality.
The Company may change the price of a Service by giving reasonable prior notice. Price changes will not apply retroactively to a current paid subscription period unless expressly agreed or required by law. Subject to applicable law, continued use of the Service after a notified price change takes effect constitutes acceptance of the new price for the next billing or renewal period.
(a) Content you post on the Platform
(i) You may post, upload or otherwise contribute content to the Platform (“User Content”). User Content includes all information, templates, materials and other content added, created, uploaded, submitted, distributed or posted to the Platform by or on behalf of the User. You are solely responsible for your User Content.
(ii) You represent and warrant that, in relation to all User Content:-
(aa) you own or have every right, licence, consent and authority required to submit, use, publish and permit the Company to process that User Content;
(bb) the User Content and its use in accordance with these Terms & Conditions do not violate applicable law, these Terms & Conditions or any third-party right;
(cc) the User Content is accurate and not misleading in any material respect; and
(dd) the User Content does not imply any unauthorised affiliation, accreditation, certification, recognition, sponsorship or endorsement by the Company or any other person.
Some User Content, including published credentials or verification information, may be publicly accessible and may be used or re-shared by others. You must use caution when publishing or sharing User Content and must review the relevant account and publication settings. The Company is not responsible for use or re-sharing by third parties outside the Company’s reasonable control.
(b) Monitoring User content
The Company may, but is not obliged to, monitor or review User Content. The Company may remove, disable or restrict access to User Content where it reasonably believes that the content breaches these Terms & Conditions, applicable law or a third party’s rights, creates a security or regulatory risk, is disputed, or may harm the Platform, the Company or another person. Where reasonably practicable and lawful, the Company will notify the User of a material removal or restriction.
(a) User content
(i) You retain ownership of your User Content. You grant the Company and its service providers a non-exclusive, worldwide, royalty-free and sublicensable licence to host, store, reproduce, process, format, adapt, transmit, display and otherwise use the User Content solely to:-
(aa) provide, operate, secure, support and maintain the Services;
(bb) implement the User’s instructions and make User Content available to intended recipients or the public, where directed by the User;
(cc) prevent fraud, investigate misuse and comply with applicable law; and
(dd) improve the technical performance and functionality of the Platform using aggregated or de-identified information where reasonably practicable.
(ii) This licence continues for as long as the User Content remains on the Platform and for a reasonable period afterwards to allow for backups, legal retention and orderly deletion, except that the licence may continue for published or blockchain-linked records to the extent technically necessary, authorised by the User, or required by applicable law. To the fullest extent permitted by applicable law, you provide the consents necessary for the Company to exercise the rights granted under this clause, including any necessary consents relating to moral rights under the applicable law.
(b) Feedback
If you provide ideas, suggestions or other feedback in connection with the Services or Content (“Feedback”), the Feedback is not confidential. You grant the Company a perpetual, irrevocable, worldwide, royalty-free and sublicensable right to use, reproduce, modify, disclose and otherwise exploit that Feedback without restriction or payment, provided that the Company does not publicly identify you as the source without your consent.
6.1 If you have questions concerning the Services or these Terms & Conditions, or wish to submit a complaint, please contact the support team at support@masverse.com.my or submit a support ticket through the Platform after logging in.
6.2 The Company will use reasonable efforts to acknowledge and address complaints within a reasonable time, taking into account the nature and complexity of the issue and any timeline required by applicable law.
(a) These Terms & Conditions continue until terminated. The Company may suspend or terminate an account, Access, payout, credential or transaction where the Company reasonably determines that:-
(i) the User has materially breached these Terms & Conditions or an applicable policy;
(ii) any amount is overdue and remains unpaid after any applicable notice or cure period;
(iii) an account, credential, listing or transaction is fraudulent, unlawful, inaccurate, misleading, infringing, unauthorised or subject to a material dispute;
(iv) there is a security, personal-data, payment, regulatory, operational or reputational risk;
(v) action is requested or required by a regulator, law-enforcement body, payment provider or competent authority; or
(vi) the relevant Service is discontinued.
(b) Where reasonably practicable and lawful, the Company will notify the User of a suspension or termination and may give the User a reasonable opportunity to remedy a remediable breach. The Company may act immediately where delay may cause harm, expose any person to liability, compromise security or breach applicable law.
(c) Except where mandatory law requires otherwise, suspension or termination for the User’s breach does not entitle the User to a refund, compensation or reinstatement, and unused Credential Credits may expire. If the Company permanently discontinues a paid Service for convenience before the end of a current paid subscription period, the Company may provide a substantially equivalent replacement, an extension, an account credit or a pro-rata refund for the unused portion, as reasonably determined by the Company and subject to applicable law.
(d) Upon termination, clauses that by their nature are intended to survive will remain in effect, including clauses concerning accrued payment obligations, intellectual property, confidentiality, disclaimers, limitation of liability, indemnity and dispute resolution.
(a) To the fullest extent permitted by applicable law, and subject to rights that cannot lawfully be excluded, the Services and Content are provided “as is” and “as available”. The Company disclaims all express, implied and statutory representations, conditions and warranties, including satisfactory quality, merchantability, fitness for a particular purpose, accuracy, completeness, availability, security and non-infringement.
(b) The Company does not warrant uninterrupted or error-free operation and is not responsible for User Content, credential accuracy or validity, recipient identity, issuer authority, public reliance, payment providers, telecommunications, cloud services, email delivery, blockchain nodes, network congestion, protocol changes, forks, cyber incidents or third-party services, except to the extent directly caused by the Company’s breach of these Terms & Conditions, negligence or wilful misconduct. No oral or written statement creates a warranty unless expressly included in a written agreement signed by the Company.
(a) To the fullest extent permitted by applicable law, neither the Company nor its officers, shareholders, employees, agents, directors, successors, assigns, suppliers or licensors will be liable for:-
(i) any indirect, special, incidental, punitive, exemplary or consequential loss or damage; or
(ii) any loss of use, data, business, opportunity, anticipated savings, goodwill, reputation or profits, whether direct or indirect,
arising out of or relating to the Platform, the Services or these Terms & Conditions, regardless of the legal basis of the claim and whether or not the relevant person was advised of the possibility of the loss.
(b) To the fullest extent permitted by applicable law, the aggregate liability of the Company and all persons referred to in Clause 7.3(a) for all claims arising out of or relating to the affected Service or these Terms & Conditions will not exceed the total fees actually paid by the User to the Company for the affected Service during the twelve (12) months immediately preceding the event giving rise to the first claim.
(c) Nothing in these Terms & Conditions limits or excludes liability for fraud, fraudulent misrepresentation, death or personal injury caused by negligence, or any other liability that cannot lawfully be limited or excluded. Nothing in these Terms & Conditions limits the User’s obligation to pay fees or amounts properly due to the Company.
These Terms & Conditions are between the User and the Company. No other person has any right to enforce any provision of these Terms & Conditions or claim third-party beneficiary rights, except that the Company’s licensors and service providers may rely on provisions that expressly protect them.
(a) To the fullest extent permitted by applicable law, the User will indemnify and hold harmless the Company and its officers, directors, employees and agents against third-party claims, proceedings, liabilities, losses, damages, penalties, costs and reasonable legal expenses arising out of or relating to:-
(i) the User’s material breach of these Terms & Conditions or applicable additional terms;
(ii) User Content or a credential issued by or on behalf of the User;
(iii) an end-user transaction for which the User is the seller, supplier or issuer;
(iv) the User’s fraud, negligence or wilful misconduct; or
(v) the User’s violation of applicable law or a third party’s rights.
(b) The indemnity applies only to the extent the claim or loss was caused by the User or a person for whom the User is responsible. The Company must give the User reasonably prompt notice of an indemnified claim, allow the User reasonable control of the defence and settlement, and provide reasonable cooperation at the User’s cost. The User must not settle a claim in a manner that admits fault by, imposes liability on, or requires action from the Company without the Company’s prior written consent, not to be unreasonably withheld.
(a) These Terms & Conditions and every contractual and non-contractual dispute or claim arising out of or relating to them, the Platform or the Services are governed by the laws of Malaysia, without regard to conflict-of-law principles.
(b) Subject to any mandatory jurisdiction of the Tribunal for Consumer Claims Malaysia or another competent statutory body, the courts of Malaysia have exclusive jurisdiction over every dispute or claim arising out of or relating to these Terms & Conditions, the Platform or the Services. The User submits to that jurisdiction and waives any objection based on venue or inconvenient forum.
(c) Before commencing court proceedings, each party should use reasonable efforts to resolve the dispute in good faith by written notice and discussion for at least thirty (30) days, unless urgent relief is required or a mandatory limitation period or statutory process applies.
(d) Nothing in these Terms & Conditions prevents the Company or the User from seeking urgent, interim, injunctive, protective or enforcement relief in any court of competent jurisdiction, including relief concerning intellectual property, confidential information, personal data, security, fraud or misuse of the Platform.
(a) The Company may amend these Terms & Conditions from time to time by giving notice through any reasonable means before the changes take effect, including by posting revised Terms & Conditions on the Platform. For material changes, the Company will use reasonable efforts to provide additional notice by email, in-Service message or another appropriate method.
(b) Changes will apply prospectively and will not apply to a dispute that arose before the effective date of the revised Terms & Conditions. Continued use of the Services after the revised Terms & Conditions take effect constitutes acceptance of the changes. If the User does not agree to the revised Terms & Conditions, the User must stop using the Services and may terminate its account by contacting the Company. The effective date at the top of these Terms & Conditions indicates when they were last updated.
These Terms & Conditions, together with all additional terms and policies incorporated by reference and any written order form or agreement signed by the parties, constitute the entire agreement between the User and the Company concerning their subject matter and supersede prior discussions, representations and agreements relating to that subject matter.
If any provision of these Terms & Conditions is held invalid or unenforceable, it will be modified to the minimum extent necessary to make it valid and enforceable. If it cannot be modified, it will be severed, and the remaining provisions will remain in full force and effect. A failure or delay by either party to enforce a provision of these Terms & Conditions is not a waiver of that provision or of the right to enforce it later. A waiver is effective only if made in writing by the party granting it.
The Company may assign or transfer these Terms & Conditions, in whole or in part, to an affiliate or in connection with a merger, reorganisation, sale of business or assets, financing or other corporate transaction, provided that the assignment does not materially reduce the User’s rights under these Terms & Conditions. The User may not assign, transfer or sublicense its rights or obligations under these Terms & Conditions without the Company’s prior written consent. Any attempted assignment in breach of this clause is void to the extent permitted by law.
The User agrees that notices, disclosures, invoices and other communications may be provided electronically through the Platform, by email to the address associated with the account, or by another electronic method agreed by the parties. The User must keep its contact information current. A notice is deemed received when made available through the Platform or sent to the User’s registered email address, unless the sender receives a delivery-failure notification.