This took me a few days to get up and running, however there were really a few errors that took time to track down, so I figured I'd post my resolutions here...maybe it saves someone else the time! My overall opinion is that your instructions were easy to follow, yet it would have been easier if you left file contents in order as generally 90% were already there and 10% needed to be added. Also it would be helpful if "domain" and "user" had more specific examples and if you differentiated between domain (e.g. example.com) and fully qualified hostname (e.g. mail.example.com).

Error:
postfix/lmtp[563]: …status=deferred (connect to /var/imap/socket/lmtp[/var/imap/socket/lmtp]: Permission denied
<br/>
Resolution:
ensure /var/imap permissions are cyrus:mail 750 (not cyrus:cyrus)

Error:
Couldn’t connect to mailbox after being created.
<br/>
Resolution:
createmailbox user.jdoe

setaclmailbox user.jdoe jdoe all

quit

Error:
postfix/trivial-rewrite[502]: warning: do not list domain example.com in BOTH mydestination and virtual_mailbox_domains
<br/>
Resolution:
In /usr/local/etc/postfix/main.cf set mydestination = (leave blank)

Error:
Postfix/smtpd[557]: warning: unknown smtpd restriction: “reject_unkown_sender_domain”
<br/>
Resolution:
remove, appears to be a smtpd_recipient_restriction

Hints:

• Define all e-mail addresses, user ids, etc in lowercase


• NTLM required in SASL2 for Outlook support


• Defining SASL users seemed to require the full hostname jdoe@mail.example.com as jdoe@example.com did not work.


• Defining Postfix virtual users:
  john.doe@example.com jdoe@example.com


• Testing IMAP: /usr/local/bin/imtest -m login -a jdoe

• http://www.postfix.org/basic.html


• http://asg.web.cmu.edu/cyrus/download/imapd/install.html


• http://www.doorbot.com/guides/sendmail/securemail/


• http://www.bsdforums.org/forums/showthread.php?t=10424


• http://www.lnxsys.ca/docs/postfix-cyrus-FC2/

Next up, securing the whole thing with OpenSSL and adding the spam filter.