sendmail - how to unknown local user

Question

I'm using debian as my webserver and sendmail as my MTA I do NOT have mydomain.com in the hosts file. I have setup sendmail.cf with the following

dnl # Masquerading options
FEATURE(`always_add_domain')dnl
MASQUERADE_AS(`mydomain.com')dnl
FEATURE(`allmasquerade')dnl
FEATURE(`masquerade_envelope')dnl
FEATURE(`masquerade_entire_domain')dnl
MASQUERADE_DOMAIN(`mydomain.com')dnl

However user@mydomain is still being reported as an unknown user by sendmail.

What am I missing?

Answer 1

Sendmail by default auto-configures list of local email domains.
It can be tuned off by the following line in sendmail.mc:

define(`confDONT_PROBE_INTERFACES',`True')

You can check list of local email domains using

echo '$=w' | sendmail -bt

You can manually add domains to local email domains via /etc/mail/local-host-names file (one domain per line). `

Standard reminders:

• sendmail.mc needs recompilation into sendmail.cf
• sendmail daemon needs to be restarted or send HUP signal to see new version of sendmail.cf