Qpsmtpd:resolvable fromhost
NAME
resolvable_fromhost
SYNOPSIS
Determine if the from host resolves to a valid MX or host.
DESCRIPTION
The fromhost is the part of the email address after the @ symbol, provided by the sending server during the SMTP conversation. This is usually, but not always, the same as the hostname in the From: header.
resolvable_fromhost tests to see if the fromhost resolves. It saves the results in the transaction note resolvable_fromhost where other plugins can use that information. Typical results are:
a - fromhost resolved as an A record mx - fromhost has valid MX record(s) ip - fromhost was an IP whitelist - skipped checks due to whitelisting null - null sender config - fromhost not resolvable, but I<reject 0> was set.
Any other result is an error message with details of the failure.
If resolvable_fromhost is enabled, the from hostname is also stored in resolvable_fromhost_host, making it accessible when $sender is not.
CONFIGURATION
reject < 0 | 1 | naughty >
If reject 1 is set, the old require_resolvable_fromhost plugin behavior of temporary rejection is the default.
resolvable_fromhost reject [ 0 | 1 | naughty ]
Default: 1
reject_type
reject_type [ perm | temp ]
Set reject_type perm to reject mail instead of deferring it.
Default: temp (temporary, aka soft, aka 4xx).
EXAMPLE LOG ENTRIES
80072 (mail) resolvable_fromhost: pass, googlegroups.com has MX at gmr-smtp-in.l.google.com 80108 (mail) resolvable_fromhost: pass, zerobarriers.net has MX at zerobarriers.net 80148 (mail) resolvable_fromhost: pass, uhin.com has MX at filter.itsafemail.com 86627 (mail) resolvable_fromhost: palmalar.com has no MX 86627 (mail) resolvable_fromhost: fail, palmalar.com (SERVFAIL)
AUTHORS
2012 - Matt Simerson - refactored, added: POD, tests, reject, reject_type
2002 - Ask Bjørn Hansen - intial plugin
