Most of these modifications to sendmail can easily be adapted to work with older sendmail versions, but you should upgrade to at least version 8.11.6 to avoid known security vulnerabilities. I have not tested this approach with any versions of sendmail 8.12 or newer but it should work with some changes.
I no longer support these modifications. Apply them at your own risk!
First apply this patch to the
source. If for some strange reason you choose not to implement any of
the anti-spam rules in the .mc file this patch should be
harmless.
Then ensure that your sendmail executable is compiled with
MAP_REGEX defined. One way to do this is to include the
line
APPENDDEF(`confMAPDEF', `-DMAP_REGEX')in your
devtools/Site/site.config.m4 file before compiling.
Add these rules to the end of your
.mc file, build a new .cf file with it,
install, and restart sendmail to make all of the changes take effect.
Don't forget to include your favorite external blacklists. Mine are:
FEATURE(`dnsbl', `zen.spamhaus.org', `"550 Mail from " $`'&{client_addr} " refused - see http://www.spamhaus.org/"')
FEATURE(`dnsbl', `bl.spamcop.net', `"450 Mail from " $`'&{client_addr} " refused - see http://spamcop.net/bl.shtml"')
Finally, here are a few entries you will surely want in your sendmail
access file:
Connect:127.0.0.1 OK From:Do_Not_Reply@paypal.com ERROR:5.7.1:550 Probable Mimail.J worm rejected From:FUCKENSUICIDE@HOTMAIL.COM ERROR:5.7.1:550 Probable Dumaru worm rejected From:hotmail.com IGNORE ZonelessDate From:msn.com IGNORE XMSMailPriority From:security@microsoft.com ERROR:5.7.1:550 Probable Dumaru worm rejected To:Friend@public.com POISON big@boss.com ERROR:5.7.1:550 Sobig.A worm rejected check@user.com ERROR:5.1.1:550 User unknown hahaha@sexyfun.net ERROR:5.7.1:550 Hybris worm rejected joe@nowhere.com ERROR:5.1.1:550 User unknown test2@test2.com ERROR:5.1.1:550 User unknown test@test.com ERROR:5.1.1:550 User unknown test@test.net ERROR:5.1.1:550 User unknown verify@email.com ERROR:5.1.1:550 User unknown verify@pisem.net ERROR:5.1.1:550 User unknown verify@testmail.com ERROR:5.1.1:550 User unknown