Open Mozilla Thunderbird
go to New -> Account

Note: if you perfer to use IMAP rather than POP3 substitute
imap.mailanyone.net in place of pop.mailanyone.net in all cases below.  Which should I Use?

Select Email account and click Next.

Type your name as you want it to appear on outgoing emails.
Then, type your email address in the field labeled Email Address.
Click Next to continue.

Select the radio button labeled POP.
Enter pop.mailanyone.net in the field labeled Incoming Server.
Enter smtp.mailanyone.net in the field labeled Outgoing Server.
Click Next to continue.

Note: The field Outgoing Server is only visible during the setup of Mozilla Thunderbird's first email account.  If you already have an email account set up, you will not see this field.

The next screen, User Names, should already be filled out correctly.  Confirm that both fields match your mailanyone username, and then click Next to continue.

Note: If you have already set up an email account, the Outgoing Server field will not appear.

Click Next on the Account Name page to accept the default Account Name.
Click Finish.

Immediately after clicking finish, you will be prompted for your password.  If you'd like to save your password, make sure Use Password Manager to remember this password is checked before clicking on OK to continue.

Change your SMTP settings as follows

Change the outgoing port from 25 to 2500

25 is default when you setup your account on your computer.  You only need to change this if you connect to the Internet through SWBell or ATT or otherwise cannot send mail