Outlook
Tools > Options > Accounts
Mail > [Properties]
Servers
Outgoing mail (SMTP): rsxxx.realsender.com
Outgoing Mail Server
[x] My server requires authentication
[Settings…]
Outgoing Mail Server
[x] Log on using
Account name: (the one we sent you)
Password: (the one we sent you)[x] Remember password
[OK]
Advanced
Outgoing mail (SMTP): 25
[x] This server requires a secure connection (SSL)
[OK]