Terms of Service and Acceptable Use Policy

By using Mailsac (also “mailsac”, “we”, “us”, “this/the service”, “this/the website”, “this/the site”), you accept these terms and the Privacy Policies and agree to abide by them at all times with no exception. You accept that any of these policies and procedures will be available on the website but that they may change at any time without notice. You have been warned.

Terms and policies apply to paid and unpaid features on this website.

Warnings and acceptable use

  • Illegal is defined as against the law in the United States, the State of California, and the applicable jurisdictions of the end user (you).
  • This website can never be used to break the law.
  • You will not send unsolicited spam to or from this service and you will comply with CAN-SPAM as well as applicable international, national, and local spam laws in your jurisdiction and the State of California, United States.
  • This website and its overseers may cooperate with legal enforcement authorities to uphold law enforcement.
  • This website can never be used for malicious activity, terrorist activity, planning illegal activities, discussing illegal activities, gambling, pornography, or condoning illegal activities.
  • This website can never be used to spread spam, untruth, gambligg, pornography of any kind whether legal or illegal.
  • Apparent terrorism or threatening behavior, harmful messages or usage to conduct intolerant or hateful or discriminatory actions, whether carried out, intended, or simulated, proven or unproven, will be blocked and removed without notice, and potentially handed over to the proper authorities.
  • This website reserves the right to block or delete mail without any notice or reason.
  • You agree to be a good citizen of this service and will not engage in any activity which degrades the quality, experience or integrity of it.
  • This service reserves the right to delete or block any email for any reason without notice and without stating any reason.
  • Unless otherwise indicated, by using the service you acknowledge that all of your incoming emails are public, not private, and unsecured, and not under copyright or ownership.
  • This service makes no guarantees about how long email will be retained, neither minimum nor maximum, or that email will be accepted or received.
  • This service is offered for use with no warranties and makes no promises that it will function as intented or unintended.

Non-commercial use

Personal (where personal is non-business and non-commercial) use of this website is free.

When using this service within the confines of any business operations, even once, necessitates the purchase of a yearly license. Incorported or non-incorporated business use is prohibited without a paid recurring active commercial subscription.


This site provides public email service. Email inboxes that are not purchased (aka private) are public and have no privacy whatsoever.

Private addresses will not be accessible publically and access to messages will be provided only to those with a validated username and password. If you believe your username or password has been compromised, you must contact the support email address immediately. This website does not accept responsibility for damages done by compromised accounts. Users acknowledge that overseers and associates (internal or external parties) may have access to inbox contents for the purpose of ongoing business operations, but that access and insight will be limited based on direct need (billing help, troubleshooting, and development comprise the standard reasons for such access, but others may apply).

Messages receipt is not guaranteed. While this service does not intent for messages to be altered, there may be arbitrary changes whether during transit or storage which are made without knowledge of the user. We cannot guarantee accuracy of any email content. Furthermore this service does not know the quality, truthfullness, correctness, or origination of messages received. Users acknowledge this and will not hold the website responsible for the content of messages.

Outgoing mail may be purchased at cost and may be delivered by a third party. The user and sender of this mail is responsible for the content they send. Delivery cannot be guaranteed but may not be refunded due to incurred costs of attempted delivery. Contact the email support address if delivery appears to be failing.

The user acknowledges that SMTP is 1) insecure by design, 2) a fail-prone protocol, and 3) a “legacy” technology which lack modern security best practices.

Outgoing mail may be marked as spam by receivers or intermediary deliverers. This website is not resonsible for email marked as spam and cannot refund such mail which is marked as spam or undelivered or unviewed. In the event that legal expenses are incurred for the sending of messages/email, those will be the responsibility in full of the owner of the account from which the messages originated, whether or not they were sent intentionally or during a period that the account was compromised. It is the responsibility of the account holder (user) to secure their account and contact support via when it appears to have been compromised.


Inbound and outbound email traffic is throttled due to various factors, including but not limited to: IP addresses, email addresses, domains, frequency of inbound or outbound mail. Banning traffic happens in rare occasions, permanently or temporarily.

We reserve the right to throttle API access, even for paid customers. Such situations are rare, but may be necessary to ensure quality of service for all other customers.


This service follows a best-effort policy to maintain uptime. No service level agreement exists, for any customer, paying or non-paying, personal or commercial.

Customers wanting service uptime guarantees should contact sales.


Mailsac provides an API service, with free and paid tiers. This service is not responsible for adverse effects in any situation, including but not limited to: API downtime, API changes, API incompatibility, lack of API support for a particular language.

Data and retention

Deleted data (including messages/email) are removed from the servers and the databases using standard deletion practices. However we cannot guarantee that backups may not exist or that business partners (such as hosting companies) will delete this data. Services which crawl publically available content (most emails on this website are public) may retain that information indefinitely and this website is not responsible. This website makes no guarantees about retention practices but intends to have deleted content be deleted. Standard application logs and failed attempts to pass data between internal services may be retained for troubleshooting.

Saved or ‘starred’ messages are intended to be retained up to the indicated limits on an account.

We are not responsible for lost data. It is the user’s responsibility to backup or retain any data they may wish to keep.

If data retention is a concern – whether keeping or removing data – it is recommend that the user do not use this service, and find another service upon which to rely.

Usage metrics are tracked, including IP addresses of site users, API users, and SMTP connections, and derivable data from service activities. Analytics on received SMTP messages are recorded. All of this data may be shared with third parties including being packaged and resold, or made available via API to paying or non-paying customers. This data can be used internally to study spam, or learn about users to provide more compelling services.


Refunds are not provided. All purchases are final. Refunds may be provided soley at the discretion of this website and its overseers. As a general rule, refunds are never given for any reason. In the event the service is down or ceases to operate, any unused services and remaining service purchases are not refunded.


These Terms may change from time to time and all updates will be posted on this website. Users of the site will not be notified of changes, and must check this website on their own if changes are of concern, or arrange with a support technician to receive updates directly from this service.


This service retains the right to revoke or deny access to anyone at anytime, with or without stated reason. Likewise any user may cease using the service and request that data be removed, in accordance with the data and rention policies outlined herein. As indicated above, refunds are not given.