At this point everything should be working. Just setup an account and check. To log in via email client apps you must use full email address as the username and the client must be capable of and enabled for smtp authentication.

If you need more testing...

Here are the tests to see if everything is working (from your terminal):

telnet localhost 25

If everything is OK, telneting to localhost 25 should respond with

Connected to localhost.
Escape character is '^]'.
220 maxo ESMTP Exim 4.24 Sat, 15 Nov 2003 07:41:39 -0800

And now we can test POP and IMAP one after the other:

telnet localhost 110

If everything is OK, something like this will appear:

Connected to localhost.
Escape character is '^]'.
+OK Hello there.

telnet localhost 143

* OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE STARTTLS] Courier-IMAP ready. Copyright 1998-2003 Double Precision, Inc. See COPYING for distribution information.

All logs are visible through Console app, however they are located as indicated below.

Courier-imap/SpamAssassin: /var/log/mail.log

Exim: (If you don't see "reject.log" or "panic.log", it's probably because exim hasn't rejected anything "yet".)

/var/spool/exim/log/exim_main.log
/var/spool/exim/log/exim_panic.log
/var/spool/exim/log/exim_reject.log

ClamAV: /var/log/clamd.log
FreshClam: /var/log/clam-update.log

Debuging by looking at logs

How to turn on loging for MySql: It is recommended to leave it "on" only for "debuging" purposes.

open -e /System/Library/StartupItems/MySQL/MySQL

Edit line 9: "/usr/bin/mysqld_safe --user=mysql &"
to look like this: "/usr/bin/mysqld_safe --log --user=mysql &"

Use your terminal to display activity from your log file. (The name of your mysql logfile is usually your computer's hostname ending with .log on your system).

tail -f /var/mysql/localhost.log

To watch what courier is doing during activity:

tail -f /var/log/mail.log

To check on Exim in "debug" mode: (You will have to kill the current Exim process)

killall exim
/usr/exim/bin/exim -bd -q30m -d

To start Exim again manually:

/usr/exim/bin/exim -bd -q30m

To start SpamAssassin in "debug" mode: (You will have to kill the current spamd process)

/usr/bin/spamd -D -x -q -Q -L --ident-timeout=0

To start SpamAssassin manually:

/usr/bin/spamd -d -x -q -Q -L --ident-timeout=0

To start/stop IMAP/POP manually:

/usr/courier-imap/libexec/pop3d.rc start
/usr/courier-imap/libexec/imapd.rc start

/usr/courier-imap/libexec/pop3d.rc stop
/usr/courier-imap/libexec/imapd.rc stop

To start Clam AV manually (use Activirty Monitor to kill any running "clamd" and "freshclam" processes):

/usr/clamav/sbin/clamd
freshclam -d -c 1 -l /var/log/clam-update.log

Test Courier authentication via terminal

cd /usr/courier-imap/libexec/authlib/
./authtest -s pop3 user@example.com password

To check Courier version installed on your computer:

/usr/courier-imap/bin/imapd --version

To check Exim version installed:

/usr/exim/bin/exim -bV

To check your ClamAV version:

/usr/clamav/sbin/clamd -V

—by George Szekely