General Policy

This domain does not permit unsolicited bulk email (spam) or other forms of abuse. Appropriate measures are in place to deal with abuse, including reporting to the appropriate authorities.

As a consequence of this policy, all mail senders must have valid abuse and postmaster mailboxes (cf. RFC 2142 and RFC 5321) that are monitored by a human, and appropriate action must be taken on complaints, including the termination of accounts for repeat offenders. Note that most victims of spam never make a complaint, so an abuse complaint must be taken seriously and investigated thoroughly.

Responding to a complaint indicating that you have taken action is a good way to prevent blocking. If you do not provide a response, or only an automated response, or you indicate no action is taken, we will interpret that as approval of the abuse.

Some users at this domain do not accept HTML email, and mail sent here should have a text/plain part that consists of appropriate plain text content that communicates the idea clearly. Mail consisting of text/html content without an equivalent text/plain alternative may be rejected. Notably, providing a text/plain part which says something like ``Please use an HTML-capable reader`` is a great way to be blacklisted.

Callbacks (also known as callouts) are abuse and not permitted.

For best acceptance, you are encouraged to send your text content email as either US-ASCII or UTF-8. Acceptance of other character sets, particularly those starting with windows-, is not as good.

Mail is considered unsolicited unless the user has explicitly opted in to receive it and proof of opt-in has been recorded. If a user opts out of receiving mail, it becomes unsolicited at that point without further delay. The sending of surveys or requests for feedback related the sale or provision of goods or services is presumed to be unsolicited unless proof of opt-in is provided. Sending of mail in a language that the user does not read or speak is presumed to be unsolicited.

Mail is considered bulk if substantially similar messages have been sent to more than one email address or repeatedly to the same email address. Messages need not be identical to be bulk.

Your domain and IP space are expected to have valid WHOIS information at all times. Domain hiding services are often used by abusers and may impair the deliverability of your email. The person or organization listed in the WHOIS information is directly responsible for compliance with this policy, and all burden of proof lies with the sender.

We make use of multiple blacklists here. Harassing blacklist operators or anti-spammers may impair the deliverability of your email.

Minimize the number of connections from your server. Multiple messages can and should be sent over one connection. Also, back off reasonably after multiple unsuccessful attempts. Hammering the mail server will result in a block.

Local parts at this domain are all lowercase, as we run Unix. The RFCs specify that a local part is case-sensitive.

Your server should make use of TLS 1.2 or later when sending email. The use of modern TLS is considered in filtering decisions.

Your server should be RFC compliant. If it’s not, your mail will probably be refused. The server administrators have noted that RFC compliance is negatively correlated with spamminess.

This policy applies to all mail-related services that involve the mail servers of this domain, including mail forwarded to this domain.

Examples of Abuse

The following are considered examples of abuse. This list is not exhaustive.

  1. Sending mail which is unsolicited and bulk for any reason.
  2. Attempting to authenticate to the server when you do not own or control an account.
  3. Attempting to deliver or relay mail through the server without authorization.
  4. Sending HTML email to a user who has not explicitly requested it.
  5. Sending mail that consists of a meaningless plain text alternative (such as “Please use an HTML-capable reader”) along with an HTML part.
  6. Attempting to enumerate users, except by using the protocol-defined methods for doing so.
  7. Making callouts or callbacks to the server.
  8. Making excessive numbers of connections to the server.
  9. Providing email addresses to third parties (any person or company not directly controlled or owned by you) for the purpose of sending surveys.

Billing Policy

Please note that dealing with abuse takes a significant amount of time. Therefore, if we make a third abuse complaint about related issues, all subsequent abuse will be billed at $500 per delivery attempt per recipient. If this is not acceptable to you, please prevent the abuse from reaching this level.

Blocklisting Codes

Several blocklisting codes are in use here. They start with an SMTP status code (e.g. 550), an extended status code (e.g. 5.7.1), a general area (e.g. IP), and then a reason code (e.g. SPAM); for example, 550 5.7.1 IP SPAM. The first two parts are well-explained by the relevant standards.

Area Codes

The sending machine, either individually or as part of a larger block, was rejected.
The sending machine’s domain, either individually or as part of a larger domain, was rejected.
The right-hand side of the envelope sender was rejected.
The envelope sender was rejected.
The HELO or EHLO argument was rejected.
The contents of the message were rejected.
The recipient of the message was rejected.

Reason Codes

Your Autonomous System (AS) is a source of repeated and continued abuse with little or no positive traffic.
Your network has a history of making legal threats either against this server or anti-spam organizations or participating in SLAPP lawsuits of any sort. For the obvious reasons, we cannot accept mail from you.
Your domain or network has invalid, inaccurate, or missing WHOIS information. Please see RFC 954 for the requirements of what must be contained.
The data in question is HTML.
The domain or network makes callouts. Please see this article, or any of the other myriad articles online, for why this is a bad idea.
This domain does not accept message/partial content.
The email address in question uses an email address local-part (i.e., the part before the at sign) that contains uppercase characters. As local-parts are case sensitive and this domain uses the standard Unix practice of lowercase usernames for humans, the email address does not represent a valid recipient.
Your email consists of a token plaintext part redirecting the user to the HTML content.
Your email is sent in a language that none of the users here understand.
Your email contains an attachment with a filename indicating it might be malicious.
Your email is in a character set or a combination of a character set and encoding that is not accepted here.
Your email contains a subject that contains no Latin letters, and cannot be understood by any user here.
Your email indicates it was sent by a nonexistent mailer or user-agent.
Your email contains a message header that is indicative of spam.
SpamAssassin objected to your message for some reason.