smtp-auth is actually quite simple to setup in Fedora. i would refrain from usingpop-before-smtp authentication, as there are security risks in doing so. im also speaking to FC4, ive not set this up in FC5 yet. but, i imagine its probably the same, or very close. first, enable and start saslauthd. chkconfig saslauthd on /etc/init.d/saslauthd start next, add these configuration options to your sendmail.cf file. define(`confAUTH_OPTIONS', `A')dn TRUST_AUTH_MECH(`LOGIN PLAIN')dnl define(`confAUTH_MECHANISMS', `LOGIN PLAIN') generate your new sendmail.mc file, and restart sendmail. this configuration will allow outlook to use authentication. hth, and good luck!