Each email client has different ways of navigating to the settings for your email account. Outlook, Outlook Express, Windows Mail, and Thunderbird are all different.
In each case you will need to locate ‘More Settings’ in your email client and change the Outgoing Mail Server Port number from 25 to 26.
Use the following settings to manually configure your email client.
Manual Settings
Mail Server Username: username@domain.com
Incoming Mail Server: mail.domain.com
Outgoing Mail Server: mail.domain.com port 26
You should typically set your Incoming mail server type to POP3.
Supported Incoming Mail Protocols: POP3, POP3S (SSL/TLS), IMAP, IMAPS (SSL/TLS)
Supported Outgoing Mail Protocols: SMTP, SMTPS (SSL/TLS)
*** You can login to your webmail at http://www.domain.com/webmail for more extensive information. You will see several webmail client options and email client configuration information.