All you need to do is a simple search on this site
you might try
smtp auth or smtp proxy look what I found
/sbin/e-smith/db configuration set SMTPSmartHost mailserver.ISP.net
/sbin/e-smith/db configuration setprop smtp-auth-proxy enabled Passwd yourpassword Userid youruserid
/sbin/e-smith/signal-event email-update
This works on SME 6.5 and up