[wpwood3]

Here are the contents of the mailog when I tried to send an email from mailman@peachtest.com to bill@peachtest.com via Squirrelmail:

 
Mar 24 10:50:01 testserver pop3d: Connection, ip=[::ffff:127.0.0.1]
Mar 24 10:50:01 testserver pop3d: Disconnected, ip=[::ffff:127.0.0.1]
Mar 24 10:50:01 testserver postfix/smtpd[17924]: connect from localhost.localdomain[127.0.0.1]
Mar 24 10:50:01 testserver postfix/smtpd[17924]: lost connection after CONNECT from localhost.localdomain[127.0.0.1]
Mar 24 10:50:01 testserver postfix/smtpd[17924]: disconnect from localhost.localdomain[127.0.0.1]
Mar 24 10:50:01 testserver imapd: Connection, ip=[::ffff:127.0.0.1]
Mar 24 10:50:01 testserver imapd: Disconnected, ip=[::ffff:127.0.0.1], time=0
Mar 24 10:51:29 testserver imapd: Connection, ip=[::ffff:127.0.0.1]
Mar 24 10:51:29 testserver imapd: LOGIN, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], port=[38758], protocol=IMAP
Mar 24 10:51:29 testserver imapd: LOGOUT, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], headers=0, body=0, rcvd=30, sent=238, time=0
Mar 24 10:51:29 testserver imapd: Connection, ip=[::ffff:127.0.0.1]
Mar 24 10:51:29 testserver imapd: LOGIN, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], port=[38759], protocol=IMAP
Mar 24 10:51:29 testserver imapd: LOGOUT, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], headers=0, body=0, rcvd=485, sent=1654, time=0
Mar 24 10:51:30 testserver imapd: Connection, ip=[::ffff:127.0.0.1]
Mar 24 10:51:30 testserver imapd: LOGIN, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], port=[38760], protocol=IMAP
Mar 24 10:51:30 testserver imapd: LOGOUT, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], headers=0, body=0, rcvd=119, sent=900, time=0
Mar 24 10:52:58 testserver sendmail[18127]: o2OEqbZ0018127: Authentication-Warning: testserver.peachtest.com: apache set sender to mailman@peachtest.com using -f
Mar 24 10:52:58 testserver sendmail[18127]: o2OEqbZ0018127: from=mailman@peachtest.com, size=633, class=0, nrcpts=2, msgid=<58474.10.0.0.1.1269442357.squirrel@w....peachtest.com>, relay=apache@localhost
Mar 24 10:52:58 testserver sendmail[18127]: o2OEqbZ0018127: to=bill@peachtest.com, delay=00:00:21, mailer=esmtp, pri=60633, dsn=4.4.3, stat=queued
Mar 24 10:52:58 testserver sendmail[18127]: o2OEqbZ0018127: to=mailman@peachtest.com, delay=00:00:21, mailer=esmtp, pri=60633, dsn=4.4.3, stat=queued
Mar 24 10:52:58 testserver imapd: Connection, ip=[::ffff:127.0.0.1]
Mar 24 10:52:58 testserver imapd: LOGIN, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], port=[38765], protocol=IMAP
Mar 24 10:52:58 testserver imapd: LOGOUT, user=mailman@peachtest.com, ip=[::ffff:127.0.0.1], headers=0, body=0, rcvd=735, sent=203, time=0

UPDATE:
All of the test emails I have sent are sitting in /var/spool/clientmqueue