Hey Chui,

did you create the mapfile database for the authinfo?
ie: makemap hash authinfo.db < authinfo

How about all the required definitions and FEATURE settings in sendmail.mc?
define(...) and FEATURE(...) for the SMART_HOST, TRUST_AUTH_MECH, confAUTH_MECHANISMS,

what does your sendmail.mc look like?

do you have the daemon saslauthd started and running?

ilya