Quoting "Paul R. Ganci" <ganci at nurdog.com>: > I have a user who has Mac OS 10.4.8 with Entourage X. The email server > is sendmail 8.13.8 and is setup to use STARTTLS on a CentOS 4.4 system. [snip] > I have just done the usual stuff that seems to work for Thunderbird, > Evolution, Outlook, Mac Mail and the latest Eudora. On the sendmail > server side: > > define(`confAUTH_OPTIONS', `A p y')dnl > TRUST_AUTH_MECH(`LOGIN PLAIN')dnl > define(`confAUTH_MECHANISMS', `LOGIN PLAIN')dnl > > (purposely not showing the certificate config) > > On the Entourage X client side: > > Checked the box "SMTP service requires secure connection (SSL) > Checked the box "SMTP server requires authentication > Checked the box "Use the same settings as receiving mail server" > > Entourage X returns an error indicating: > > "The SMTP server for "MRIC" does not recognize any of the > authentication methods supported by Entourage." Maybe the version of Entourage you have doesn't support STARTTLS. Try enabling implicit SSL port in Sendmail's configuration by adding this line: DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s') After adding that line, Sendmail will listen on port 465 (smtps) in addition to port 25. You'll have SSL on port 465, and on port 25 you can have plaintext or TLS (after client issues STARTTLS).