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A couple of notes... using psa-spamassassin will result in all messages being scanned twice, which creates a lot of overhead.

Use the modified qmHandle's qmHandle -tt to see the top senders/recipients. Look at one of the spam messages and look at the Received line, which will either show you a UID or received from network.

If it shows you a UID, then the spam is coming from a compromised script.

Here's a typical log sequence for a message sent to a remote system from the local system:

1 @4000000038c3eeb027f41c7c new msg 93869
2 @4000000038c3eeb027f6b0a4 info msg 93869: bytes 2343 from dave@sill.org qp 18695 uid 49491
3 @4000000038c3eeb02877ee94 starting delivery 2392: msg 93869 to remote lwq@w3.to
4 @4000000038c3eeb0287b55ac status: local 0/10 remote 1/20
5 @4000000038c3eeb104a13804 delivery 2392: success: 209.85.127.177_accepted_message.

By default, vacation will not work properly with sendmail... you'll see errors such as the following:

"|/usr/bin/vacation username"
    (reason: Service unavailable)
    (expanded from: email_address)
   ----- Transcript of session follows -----
451 4.0.0 putbody: write error: Broken pipe
smrsh: "vacation" not available for sendmail programs (stat failed)
554 5.0.0 Service unavailable

By default, sendmail will begin queuing mail rather than sending it out at 12 load average, and stop refusing connections at 18 load average. These options can be changed in /etc/mail/sendmail.mc with the following variables:

define(`confQUEUE_LA', `12')dnl
define(`confREFUSE_LA', `18')dnl

This can be accomplished with the smtp_bind_address directived, e.g.

smtp_bind_address = 66.216.86.216

Here are the steps for integrating ClamAV with Plesk/Qmail:

* Stop all Plesk services and remove the drweb rpms

service psa stopall
rpm –e drweb drweb-qmail --nodeps --force

* Add the Atomic Rocket Turtle archive to the rhn sources

By default, sendmail sends from a single queue. Needless to say, this is not ideal from a performance perspective. Fortunately, setting up sendmail to use multiple queues is easy!

First, create a directory for each queue you want, e.g.

mkdir /var/spool/mqueue/q{1,2,3,4,5}

Ensure that the permissions and ownerships are correct for your mail install (should be the same as /var/spool/mqueue).

Edit /etc/mail/sendmail.cf to include a QUEUE_DIR definition with a wildcard including the appropriate directories:

define(`QUEUE_DIR', `/var/spool/mqueue/q*')dnl