Does sendmail check Reverse Domain Name?

Sanford Stein · 01-23-2014, 10:46 AM

Is there something I need to do in a sendmail configuration file so that it checks the reverse domain name of incoming mail?

I want to reject all mail from Russia. I have the following line in my /etc/mail/access file:

*.ru REJECT

I am still getting a lot of messages in maillog about mail from the .ru domain, and it does not seem to be universally rejected.

So is there something else I need to do to make this work? Is the wildcarding here legal?

Thanks,
Sanford Stein
CyberTools Inc.

Habitual · 01-23-2014, 11:30 AM

seen this?

FEATURE(`access_db') section... eg, is it enabled?

Sanford Stein · 01-23-2014, 01:33 PM

Habitual, thank you for your prompt response.

Yes, FEATURE(`access_db') is enabled.

I have read discussions on the REJECT feature of /etc/mail/access similar to the one in the link you sent. Example of using a wildcard in the domain name are not shown, but I have seen examples of them elsewhere in linuxquestions.org. I do not see a "general purpose message" in /var/log/maillog so that's why I am asking if the REJECT is working.

Habitual · 01-23-2014, 02:18 PM

I'm thinking that it may | should be .ru instead of *.ru ?

Sanford Stein · 01-23-2014, 03:25 PM

.ru seems to have same result as *.ru

Habitual · 01-23-2014, 04:14 PM

Well, then, how about

Code:

@*.ru

or some slight variation thereof?

TLD REJECT says http://www.sendmail.com/sm/open_sour...anti_spam.html

but this says wildcards aren't allowed?

Are you rehashing the db after editing and "all that" that comes with it?

Sorry I don't have a definitive answer.

Sanford Stein · 01-24-2014, 11:08 AM

Yes, definitely running 'makemap hash' after each modification to /etc/mail/access.

What I decided to do was identify the domains that are most frequently spamming us (by parsing maillog) and appended those to /etc/mail/access.
Example:
msbins.ru REJECT

Hopefully we can filter out 90+% of the spam this way.

Thanks for your help.