On the Tools menu, click Account Settings.
Click 'Microsoft Exchange, POP3, IMAP, or HTTP', and then click 'Next'.
In the Auto Account Setup dialog box, click to select the Manually configure server settings or additional server types checkbox and then click 'Next'.
Click Internet E-Mail, and then click 'Next'.
Fill out the required settings as following:
Your Name: Your name exactly as you want it to appear to recipients when they receive email from you
Email Address: your full email address - eg firstname.lastname@example.org
Account Type: IMAP (recommended)
Incoming mail server: mail.<domain> - replace <domain> with your domain name, for example mail.my-domain.com
Outgoing mail server (SMTP): mail.<domain> - same as the Incoming mail server
Username: your full email address once again
Password: your mailbox password
Ensure that 'Require logon using Secure Password Authentication (SPA) remains unchecked. This is important as you may experience difficulty sending email with this enabled.
Click "More Settings..." in the bottom right of the window
Click "Outgoing Server" tab at the top.
Tick the box labelled "My outgoing server (SMTP) requires authentication"
Click "Advanced" tab at the top
In the Outgoing mail (SMTP) box, type 25. *Note, if you have trouble sending e-mail, please try changing this to port 587.
Ensure that 'This server requires an encrypted connection (SSL) is unchecked.
The 'Use the following type of encrypted connection:' option should be set to None
Click "Ok" to close the window.
Click Next after you have completed entering this configuration information, and then click Finish.