I'm reading a lot on how to setup my smtp auth on a new Centos 6.2 server. I want to use sendmail and have this running on a Centos 3 machine now, so it's not new stuff to me. Unfortunately, the more I read, the more confusion I seem to have. Firstly, how to generate my certificates. A good recommendation or howto would be in order. I think most of the confusion here comes from the commented names of files used in sendmail.mc for all the auth files. As far as I can tell, the encryption length is the only change I need (going to a minimum of 2048 bits) from the old system generation. Those "pem" files throw me a bit, though. Secondly, I'm reading DoveCot has a problem with security and that I need to run something other than ? (Cyrus, Courier, etc) to make this work. I typically don't run imap security, only on smtp, so I'm not sure if there's to be interference between the two. Since postfix is the default now on Centos 6.2, what should I look for by changing it back to sendmail when it comes to smtp auth? I only authenticate users that are not in the building on our network to allow them to send email. They're free to use pop or imap to retrieve their email without authentication. Thanks for any clarity on this. steve campbell