I configured Postfix, after a time I discovered I am blocked from sending emails because my network is on a blacklist (it's a dynamic IP). So, sometimes Outlook does not connect to send (still gets the mails). Then I changed the SMTP on the master file and I set port 587 on this way:
587 inet n - - - - smtpd
The problem is now I can't receive, I get these errors:
The recipient server did not accept our requests to connect
On my domain manager I set the A register to point to his own IP, and the MX to point to my domain name (the MX is mydomain.com, not mail.mydomain.com, but all was configured this way with Postfix).
I don't understand what could be wrong, any idea of this issue?