Troubleshooting Problems with Postfix, Dovecot, and MySQL

Update the guide based on the comment in Disqus:
*********************************************************A couple comments that might help others avoid difficulties that I experienced in the section pertaining to Dovecot.

In Step 14 of "Virtual Domains and Users" we are given the line
mail_location = maildir:~ #update mail_location

Given the earlier instructions at the start of the section (bullet point 4), this line would be much more helpful if it were instead:
mail_location = maildir:/var/mail/vhosts/example.com/user/

In trying to interpret this instruction, I mistakenly left the "~" in when adding the address, and spent a great deal of time
wondering why emails were not being located. As I was running the tests from root, I somehow ended up with /root/var/mail/vhosts/... and of course no email there as it was being correctly sent to /var not ~/var.

Secondly, the Dovecot site has some very helpful trouble-shooting scripts (in their documentation, under "TestInstallation"). If the reader is following this guide, the place to edit for extra debugging messages to be included in the log file is at /etc/dovecot/conf.d/10-logging.conf, and the logs can be read at /var/log/mail.log. At least, that is where they are for me and I'm trying to follow the instructions as closely as possible.