[vps-mail] Greylisting, milter, milter-greylist, anti-spam, spam, luncheon meat

["Brian Haines" <providertalk@xxxxxxxxxxxxxxxx>]

So that it is all together and easy to find ;)

Bennett responded to a question about rbl's other than spamcop:

<quote guru="Bennett Lanford">
My favorite: sbl-xbl.spamhaus.org. I include the following line in my
sendmail mc file:

FEATURE(`dnsbl',`sbl-xbl.spamhaus.org')dnl

I also use greylisting, which blocks about 75% of all incoming mail. (See
FreeBSD ports: /usr/ports/mail/milter-greylist )
</quote>

In response to it being High Maintenance:

<quote guru="Bennett Lanford">
*No* maintenance ... once you set it up. milter-greylist is very well
written. It requires no MySQL databases (nothing special, actually). A good
overview of greylisting is at http://projects.puremagic.com/greylisting/ (I
don't use that particular greylisting package--I did initially, though. Now
milter-greylist is my
favorite.) There is also a greylisting website at [sic]
http://greylisting.org/

The only possible drawback is that when a sender *first* sends an e-mail to
a particular recipient on your server, your server returns a
*temporary* failure response, forcing the sending server to queue the mail
until its next queue run (typically 20-60 minutes). Compliant SMTP servers
will all queue the mail and deliver it within that time period. Windows
trojans and most spam generating programs, OTOH, won't try a second time, so
the the SPAM is never delivered. When the mail is finally delivered, that
sender/recipient/IP-address triple is "remembered" for a
(configurable) period of time--typically 5-30 days--so that subsequent
deliveries are instantaneous.
</quote>

Scott indicated that some MTAs were unable to get through until he
whitelisted them.

<quote guru="Bennett Lanford">
The end of the default greylist configuration file
(/usr/local/etc/mail/greylist.conf) lists some some mail servers that are
"broken" for greylisting. (You can add additional incoming servers that you
don't want to greylist.) I've always just used the default servers.

An early version of milter-greylist didn't include those servers. Most of
them are *big* e-mail domains like AOL and Yahoo (etc.) that have big
mail-server farms, with the servers "acting as one." I watched my logs a
year or so ago (when I first tried greylisting) as I sent an e-mail from a
Yahoo account to my VPS. Each time it tried to resend, it sent the mail from
a different server (in the pool of Yahoo servers). Finally, there was a
repeat server, and the mail got through. (It took about three hours,
IIRC.) (I hope I'm remembering the above correctly, and not spreading too
many lies.)

Occasionally I've had a user complain that an e-mail didn't arrive
instantaneously. When I tell them about greylisting, they generally think it
is a good idea. (I *love* it!!)
</quote>

An installation question was asked and Mark Sharkey replied with a link to
one of Weldon Whipple pages:

http://technoids.org/milter-greylist.html

VPS users should skip the section on ports tree updates as they are
automatically updated.

Then of course, I was having problems following directions and was given
some helpful commands:

restart_sendmail;tail -f /var/log/maillog

End with ctrl-c

That was helpful as it read the log to the screen.

Bruce Armstrong pointed out this and while double checking it I dond I had a
type:

1. Add the following to /etc/rc.conf
miltergreylist_enable="YES"

2. Start the milter:
# /usr/local/etc/rc.d/milter-greylist.sh start

If you neglect #1, #2 won't work.

Did anyone notice that I added luncheon meat the subject? I couldn't resist
:)

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