Postmaster addresses

There are two sides to postmaster addresses: the postmaster addresses for which your site accepts mail, and the postmaster addresses your site emits as the From: address on notification messages your site generates.

Domain names for SMTP servers visible on the Internet are required to be able to accept mail addressed to    . This means that any host with an Internet-facing SMTP server, and any visible-on-the-Internet hosted  domain names, are required to support a corresponding postmaster  mailbox. And indeed, it is normal and strongly recommended to have a postmaster mailbox for each and every e-mail domain name (including any  purely internal e-mail domain names) you support. The MTA itself will send warning messages and, (depending upon version) may default to  sending copies of users&#x27; bounce  messages to the postmaster.

It is critical that the postmaster address be a valid address for receiving mail! Hosting the postmaster mailbox directly on the Internet-facing SMTP server system may reduce the potential for  problems arising in forwarding a message onwards. However, in a multi-tier deployment it is possible that you will not want to have to  have someone log on regularly to the Internet-facing SMTP server system  to check postmaster mail. If you do wish to direct postmaster mail to a different system, be sure to ensure that the connection between the  e-mail Internet-facing system and that other system is a very reliable  connection; and be prepared that if something happens to break that  connection, you will want to immediately change the postmaster address  on the Internet-facing SMTP server system to some other functioning  address or be prepared for the potential for serious e-mail problems. (Bouncing postmaster mail is not pretty.) See also the   channel option  which can sometimes simplify consolidation of postmaster addresses.

The special  local-part is defined (see RFC 822) to be  case-insensitive even if local-parts in general are allowed to be  case-sensitive, and the MTA has special code to treat postmaster  case-insensitively even if it has been configured (see the    MTA option)  to allow other local-parts to be case-sensitive.

Normal MTA configuration includes at least one postmaster address as an alias (whether in the  alias file, or as an  alias in Unified  Configuration). In particular, in a modern Unified Configuration: msconfig&#x3e; show alias:root&#x2a; role.alias:root@&/IMTA_DEFAULTDOMAIN/.alias_entry = postmast role.alias:root@&/IMTA_HOST/.alias_entry = postmast msconfig&#x3e; show alias:postmast&#x2a; role.alias:postmaster@&/IMTA_HOST/.alias_entry = postmast which presumes that a valid user account (often the Messaging Server  user) is provisioned with   as a    value.

As regards what postmaster address(es) your site emits on the notification messages your site generates, the MTA has a variety of  configuration controls: the    and      MTA options  for MTA-wide defaults, the    and      channel options for channel-specific settings, and the    domain-level LDAP attribute (more  precisely, the LDAP attribute named by the     MTA option) for a  domain-specific setting, as well as potential language-specific  override of the Postmaster personal name via the    option in  language-specific      files,  or    mapping table  overrides of the  Postmaster address via     or   flags. The MTA defaults for  and   mean that the   MTA defaults to emitting as Postmaster address     where   is the     on the L channel,  and defaults to using as Postmaster personal name  " ".

Certain non-MTA options also affect the postmaster address emitted in cases of postmaster messages generated by other (non-MTA) components of Messaging Server; see also the  and   Alarm options.

See also:
 * Notification messages
 * Notification message MTA options
 * Notification message types
 * copysendpost Option
 * alias_case MTA Option
 * aliaspostmaster Option
 * return_address MTA Option
 * return_personal MTA Option
 * returnaddress Option
 * returnpersonal Option
 * ldap_domain_attr_report_address MTA Option
 * official_host_name Option
 * Local channel
 * user_case MTA Option
 * FROM_ACCESS mapping table
 * Aliases in Unified Configuration
 * Alias file format
 * noticercpt Option
 * noticesender Option