Missing Mail records problem fixed

Since we switched over to our new SmarterMail server we have had a problem with the default MX and MAIL DNS records not being created when a new domain is added in HELM.

This problem has now been resolved.

Please note however that we have to re-enable the creation of a default mailbox to achieve this due to a bug in HELM. So whenever you add a new domain a default mailbox of postmaster@yourdomain will be created.
Please do not leave this mailbox unchecked, otherwise it will use up your disk space quota as it fills up with spam. It is recommended to have a postmaster address (see below) so you may prefer to set it up as a forwarder rather than a mailbox.

In computers and technology, postmaster is a term used to identify the administrator of a mail server. Nearly every domain will have the e-mail address postmaster@example.com where errors in e-mail processing are directed. Error e-mails automatically generated by mail servers’ MTAs usually appear to have been sent to the postmaster address.

Every domain that supports the SMTP protocol for electronic mail is required by RFC 5321 and, as early as 1982, by RFC 822, to have the postmaster address. The rfc-ignorant.org website maintains a list of domains that do not comply with the RFC based on this requirement.

Quoting from the RFC:

Any system that includes an SMTP server supporting mail relaying or delivery MUST support the reserved mailbox “postmaster” as a case-insensitive local name. This postmaster address is not strictly necessary if the server always returns 554 on connection opening (as described in section 3.1). The requirement to accept mail for postmaster implies that RCPT commands which specify a mailbox for postmaster at any of the domains for which the SMTP server provides mail service, as well as the special case of “RCPT TO:<Postmaster>” (with no domain specification), MUST be supported.

SMTP systems are expected to make every reasonable effort to accept mail directed to Postmaster from any other system on the Internet. In extreme cases (such as to contain a denial of service attack or other breach of security) an SMTP server may block mail directed to Postmaster. However, such arrangements SHOULD be narrowly tailored so as to avoid blocking messages which are not part of such attacks.

Since most domains have a postmaster address, it is commonly targeted by spamming operations. Even if not directly spammed, a postmaster address may be sent bounced spam from other servers that mistakenly trust fake return-paths commonly used in spam.

If you enjoyed this post, make sure you subscribe to my RSS feed!