I use Evolution as my emailclient, and configured it to use sendmail for sending the emails. However, after a while I began suspecting sendmail not be sending my emails. And indeed, sendmail -bp showed that all my sent emails are still somewhere in a queue. Sendmail -bp showed them all like this:
(connect to mailin-03.mx.aol.com[64.12.138.57]: server dropped connection withou t sending the initial SMTP greeting)
I tried finding the file or directory where these emails reside, but did not find it.
I also tried finding the sendmail configuration file (sendmail.cf, or .sendmail) but cannot find it anywhere.
Can someone tell me why me emails are not being sent, and how I can get sendmail to work?

Thanks!

Vast majority of mail servers out there won't accept your mail if it is not coming from a trusted mail server - which means you must have valid MX records. You should route your outgoing mail thru your ISP's SMTP server.

Great.. so no use for the great sendmail tool...
Well, thanks for fixing it!

Some people use web links provided by spammers to make their purchases, spammers get paid in turn and as a final result your mail is not accepted
Your ISP's mail server accepts your mail omly because you are in their allowed IP range and this is your only guaranteed way to send mail.