i'm trying to set-up a mail server with postfix as my mta. i can already send mails to external address. i'm having trouble, however, receiving external mail. i tried sending from an free email provider and this is what it returns:
<firstname.lastname@example.org>: connect to mail2.sni.ph[18.104.22.168]: Connection
there is already an entry in my /etc/postfix/access for mail2.sni.ph and there is already and MX entry in the dns.