The Unofficial Guide to Configuring the OS X Mail.app for
Andrew
Mail.app is not supported by the Computing Services Help Center, but
many people want to use it anyway. The following instructions
should work, but I don't make any guarantees, nor can I provide any
support. These instructions were created and tested on OS X
10.4.4.
These instructions assume you have already installed Kerberos
for Mac and the CMU SSL Root Certificates. If you haven't done so, follow those links and install both of them now.
Launch Mail.app by double clicking on it's icon. Assuming you
haven't already set it up, you should see the following:
Click "Continue" and fill out the next page as follows:

You can set your name and email address however you prefer.
This is what the From: line on mail messages you send out
will be set to. For example, you can set your From: address
to your CMU Name if you prefer that to your Andrew address.
Click Continue, and set up the incoming server name details:

For your user name, you should set it to your Andrew user id with a plus sign
after it. (This is recommended because Apple's Mail.app does
not understand IMAP subscriptions. If you don't use the plus
after your name, it will try to list _every_ bboard on the Andrew
system, and you really don't want that.)
Leave the password field blank. Mail.app supports Kerberos
authentication, as you will see on the next panel. Click
continue, and:

Enabling SSL on this page isn't necessary, but recommended so that
people on the network can't snoop in on your email when you're reading
it. Be sure to select "Kerberos Version 5 (GSSAPI)" for the
authentication method.
Click Continue, and Mail.app should try to log in to Cyrus.
If you already have Kerberos tickets, it should take you to
the next panel. If not, it will pop up the Kerberos login box:

Log in, and you should be taken to the next panel.

Set the outgoing mail server to smtp.andrew.cmu.edu, and check the Use
Authentication check box. On this panel, you want to enter
your Andrew user id without the plus -- sending mail doesn't require it (and
won't work with it). Again, leave the password field blank.
Click continue, and it will verify the outgoing mail settings.
Assuming all went well, you will be shown a summary panel.
Click continue, then Done on the final panel, and Mail.app
should launch and run. It will probably ask you about
importing mailboxes from another client (which you probably don't need
to do).
You should now be able to read your mail, and access all of your
subscribed bboards from Mail.app. Enjoy!