Outlook Express under Windows

Open Outlook Express
Tool → Accounts
Click Add → Mail to start the Account Wizard
Display name: Your Name
E-Mail address: Your email address (ex. bill@microsoft.com)
Select POP3
Incoming Mail server: mx.sdf.org
Outgoing mail (SMTP) server: mx.sdf.org
Account name: Your email address (full email address for VPM and VHOST members, just username for MetaARPA)
The wizard will now save, double click on the new configuration under the Mail tab to continue
Select the Advanced tab
Outgoing mail (SMTP) change from 25 to 587 (not completely necessary, but recommended)
Select the Servers tab
Check the box 'My server requires authentication, then click Settings
Select Log on using:
Account name: YOUR DOMAIN NAME (ex. alan8r.sdf.org, traumhost.com)
Password: What you set with the mkvpm set secret command at the shell
Click 'Apply'
Mail.App under Macos X
Open Mail.app
In the Mail menu, select Preferences
Click the Accounts tab
Select the account on the left you wish to edit
On the Account Information tab, find “Outgoing Mail Server (SMTP):”
Click the arrows for the dropdown menu, and select Edit Server List…
Make sure the server you wish to use is selected in the list, and click on the Advanced tab
In the Authentication dropdown, select “MD5 Challenge-Response”
Type in your SDF username in User Name field
Type in your password in Password field
Click ok, and close the Preferences window.