Mail between local domains bounced

[GuzziGuy]

I discovered that the Vesta exim conf has a feature that may not work for some folk. Specifically that mail between local domains (the same or different domains) will bounce back if it was not received via an authenticated connection.

Most users would send via their own authenticated account, so for them it's not an issue. However, I found some users were sending unauthenticated via eg their ISP's SMTP server, which should be fine but prevents mail between them. Ie:

• user@localdomain1 > user@externaldomain - fine
• user@externaldomain > user@localdomain1 - fine
• user@localdomain1 > user@localdomain2 - bounced back from exim

The ideal answer, of course, is to just ensure that all mail from any local domain is sent via an authenticated account. But this isn't always possible. The fix, then:

Code: Select all

/etc/exim4/exim4.conf.template - find acl_check_receipt then comment out:

#  deny    message       = smtp auth requried
#         sender_domains = +local_domains
#         !authenticated = *

sudo service exim4 restart

I guess this is in place to stop spammers sending to you@yourdomain from them@yourdomain - but they could of course send to you@yourdomain from them@theirdomain. I don't see any other issue with disabling this; the same relay restrictions otherwise remain in place.

Hopefully this saves somebody the same amount of confusion that I had!