> probably the best way to handle the "travelling user" need is with > smtp-auth -- where the sending client authenticates. > > look at/for the following lines in your sendmail.mc > > > dnl # The following causes sendmail to additionally listen to port > 587 for > dnl # mail from MUAs that authenticate. Roaming users who can't reach > their > dnl # preferred sendmail daemon due to port 25 being blocked or > redirected find > dnl # this useful. > > > the concept of temporarily adding a random/dynamic ipnumber isn't > very good as it open a (admittedly probably small) window that might > be able to be used by a spammer type should they come upon it. > Thank you very much for the help! I uncomment the line DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl but, I have a question: if outlook express does not use port 587, then what to do? How to make sure that if outlook express finds port 25 blocked, it will try port 587? What about the other line dnl DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl does that help if it is uncomment too? Thanks! Hongwei