MetaARPA, VPM or VHOST memberships allow you, as an SDF user, to set up additional email accounts–Virtual Private Mailboxes–without creating separate SDF users, and give you access to the SDF SMTP servers to send mail from your computers and devices.
After paying appropriate dues, you can set up your VPM with the SDF program mkvpm
. For more information, see the mkvpm faq page