Docs for http://www.qmail.org/qmail-remote_authenticated_smtp.patch a patch to convince qmail-remote to use Authenticated SMTP when talking to certain hosts. After applying the patch, the username password go into /var/qmail/control/smtproutes like so: domain:relay The domain:relay part is identical to a normal smtproutes entry (see the qmail-remote man page). For sites that require authentication, you simply add two space separated fields to the line, where the first field is the username, the second is the password. Both fields must be base64 encoded. For example: inside.af.mil:firewall.af.mil:26 am9obmRvZQo= c2VjcmV0 would send mail for inside.af.mil to firewall.af.mil, port 26 using username 'johndoe' and password 'secret' You may base64encode the username and password with the following simple Perl script: % perl -e 'use MIME::Base64;print encode_base64($ARGV[0])' johndoe am9obmRvZQ== % perl -e 'use MIME::Base64;print encode_base64($ARGV[0])' secret c2VjcmV0 Note that base64 encoding is NOT secure - so you might want to make smtproutes owned by qmailr and set its permissions to 0600. Of course, the base64 encoded entries are going to go over the wire in the clear anyway as part of the SMTP transaction. Good luck. j.