I set up my mail server with Webmin/Virtualmin with Postfix couple days ago. Server lives on EC2 instance. Everything was working just fine. Mails were being send and I recived them properly as well. I didn't only pass MX records tests. Since that time the only thing I messed up with were MX Records in DNS Records - those change allowed me to pass tests on mail-tester. I also had some prompt about updating packages, so I did update them. After that I tested my mail server (but only sending message - it was ok). Today I wanted to use mailbox once again (to warm up my IP) and noticed that I can send email, but didn't recive any. However emails send from my mailbox to my mailbox (the same address, so internal) are being recived. So only emails from outside are not coming through.
What I tried:
-checked my Security Group on EC2 instance - It's just fine - I allow port 25 and all other from everywhere (except SSH :22 of course). So it doesn't look like firewall issue (especially that it was working and I didn't mess up with them)
-Checked postconf -n and I realized there are Warnings:
postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_sender_restrictions postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_client_restrictions postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_helo_restrictions postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_sender_restrictions postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_client_restrictions postconf: warning: /etc/postfix/master.cf: undefined parameter: mua_helo_restrictions
So I found this thread: Warning `undefined parameter: mua_sender_restrictions` when `postconf -n` sender-restrictions-when-postconf-n and I got rid of Warnings by adding to my main.cf file lines:
smtpd_restriction_classes = mua_sender_restrictions, mua_client_restrictions, mua_helo_restrictions mua_client_restrictions = permit_sasl_authenticated, reject mua_sender_restrictions = permit_sasl_authenticated, reject mua_helo_restrictions = permit_mynetworks, reject_non_fqdn_hostname, reject_invalid_hostname, permit
That way Warnings disappeared but problem persists. I still cannot recive any mails form outside.
EDIT: Solved. The problem was invalid dkim record.
