I am running Sendmail 8.13.3 on Yellowdog 3.0. There is a company that tries to email us sometimes that sends automatically generated emails (no, not spam). Unfortunately when they do this, the don't use their normal host name. The "mail from:" tag has root@unix.rjy.corp. Now there is no domain called unix.rjy.corp (nor could there be). Sendmail rejects these emails everytime.

I want to know how to get sendmail to accept them despite the fact it is a not existing domain. In my sendmail.mc I have
FEATURE(`accept_unresolvable_domains')dnl

I would think this would solve my problem (and yes, I created the .cf file and restarted sendmail)

I have also added
From:unix.rjy.corp OK
to my access file and created the access.db file

I have an internal DNS server and my next step is to add unix.rjy.corp to the list of names to at least give some false validity to the host name.

I would rather find a real alternative rather than the quick fix so I don't have to deal with it the next time some ass clown misconfigures their mail server. Any help would be much appreciated.

Personally, I would not enable FEATURE(`accept_unresolvable_domains')dnl, thats a global setting. Nor would I add a bogus DNS entry to my DNS server. But these are viable solutuons to your problem.

Adding the "From: bogus@wrongdomain.com OK" to the access file would be the solution I would use if these e-mails are always going to have the same envelope sender. Maybe even adding "Connect: [IP of MTA sending e-mail]" might be a valid alternative. But if the sender of these e-mails is always going to change the From: address to be bogus so that no one can reply, then I see no easy solution other than the accept unresolvalbe domain feature. <groan!>

Good luck!

I tried adding a 'connect' line and that did not work either. I don't like having to have FEATURE(`accept_unresolvable_domains')dnl but it is neccessary because of some other domains that aren't properly configured that we need to communicate with. We were tired of people telling us we were wrong about them being misconfigured when we had to proof. It was turning out to be more hassle than it was worth.

But that's OK because we use several DNSBL services and that kicks back about 40% of incoming emails that are all junk.

I think I will have to resort to adding a fake DNS entry. It won't be that bad considering it is not out primary DNS server but it just seems like a dirty hack. I appreciate your help on that. I didn't even think about a Connect statement.