Thunderbird Authenticated SMTP Configuration
First thing you need to do is request a CS Kerberos5 Password from
staff. This is different (for now) than your unix password.
You will use your username in CS and the CS Kerberos5 password to
authenticate you with the smtp server. The first thing you will
need to do is install our certifcate because we are not in the default
certifcate chain in your browser.
You first need to go to http://www.cs.umd.edu/certs
and right click on the "CSD Certificate in cer/pem format" and select
Save As... and save it locally into the file system.
Then go to Tools->Options and select Advanced. Then click the Manage
Certificates... button.

Now move over to the Authorities tab and choose import.

And select the cacert.cer file that you downloaded and select Open.

Now click all three checkboxes and select OK.

Go to the Tools menu
and find the Account Settings... and click on it.
Find the Outgoing Server (SMTP) settings and make sure that the server
name is smtp.cs.umd.edu, then make sure that the User
Name and Password
checkbox is checked and put in your CS Username into the user name
field. Finally make sure that Use secure connection, TSL option
is set. (NOT TLS, if available)

You can now close your preferences when you send mail the first time it
will ask you for your CS Kerberos5 password and you can choose
then whether or not to save that password for future use.
Some ISPs block port 25 outgoing. If this is the case with you you can
use port 587 in Outgoing Server SMTP pane in the Account Settings.