My email should be OK. I can receive, and send via webmail. But sending from Thunderbird or evolution results in: 1. the password box popping up a few times Then I get: 2. Sending of message failed/ The message could not be sent because connecting to SMTP server mx.mydomain.com failed. The server may be unavailable or is refusing smtp connections. Please verify that your smtp server setting is correct and try again, or else contact your network administrator. maillog gives me: postfix/sendmail: fatal: usage: sendmail [options] Other things are fine. To add to the problem, I can not test from here since my ISP blocks port 25 and I use the ISPs SMTP for sending. On the other side it worked before and I used to use mx.mydomain.com. I just moved that domain in question to my new VPS. Server is CentOS 5.2 with Dovecot, Sendmail, Postfix Help is greatly appreciated.