domain_for_unqualified_recipient_addresses

March 26, 2020 Contributors

Name

domain_for_unqualified_recipient_addresses — configure a domain which will be used to resolve delivery for unqualified addresses

Synopsis

domain_for_unqualified_recipient_addresses = "example.com"

Description

RFC-2821, section 4.5.1, requires that all compliant MTA’s accept the special address of "RCPT TO:" without a domain name. Mail sent to this address should normally be forwarded to the entity responsible for the MTA as a whole, not some specific domain being accepted by that MTA. To make this support more flexible, domain_for_unqualified_recipient_addresses will actually support any unqualified e-mail address. For example, a site may wish to also support "RCPT TO:" as an alias, as suggested by RFC-2142.

When set, domain_for_unqualified_recipient_addresses will rewrite the envelope address internally, although the original "RCPT TO:" is still available from Sieve during all rcptto and data phases, using vctx rcptto_string. The envelope address is actually rewritten before the each_rcpt phases, and will now use the expanded address when relayed to the final destination. The trace headers, however, will reflect the original "RCPT TO" string. NOTE that the "TO:" header in the e-mail is never rewritten.

domain_for_unqualified_recipient_addresses is valid in either a global scope (for a single fallback domain for all unqualified addresses) or can be set in a Pathway scope (for specific fallback domains for any number of specific domains). The more specific Pathway scope overrides any existing value set in a global scope.

To accept unqualified "Postmaster" mail for the entire MTA, one would specify

domain_for_unqualified_recipient_addresses = "example.com"

which would rewrite any message sent to "RCPT TO:" as if it had originally been written "RCPT TO:[email protected]" .

Scope

domain_for_unqualified_recipient_addresses is valid in pathway, pathway_group, global, and listener scopes.