Setting up Outlook to send through SMTP on port 587
Many ISPs are now blocking port 25 outbound from end users to prevent spam from their network. A new standard is to use port 587 and setup exim to listen on port 587.
To setup Outlook to do this
1) Open Outlook.
2) Tools -> Accounts
3) go to the "Mail" tab.
4) select the account and click "Properties".
5) Go to the "Advanced" Tab in the new window.
6) Set the "Outgoing mail (SMTP)" option to 587 from 25. Hit "Ok".
Outlook should now use port 587 for sending mail.
You'll need to make sure you have exim listening on port 587.
You can do this by Installing the latest "SpamBlocker Version 2" or by using the related guide below.