Amazon SES does not deliver mail to our domain

Hello, I am a system administrator in our company mail infrastructure.

We are observing strange behavior of Amazon SES servers as soon as mails are approaching our domain. The SES outgoing server waves its EHLO and disconnects right after instead of actually sending e-mails waiting for recipients in our domain.

From our servers' logs, the behavior is observed as:

Jan  7 16:36:58 produkcyjny: connect from a113-214.smtp-out.us-west-2.amazonses.com[54.240.113.214]
Jan  7 16:36:58 produkcyjny: lost connection after EHLO from a113-214.smtp-out.us-west-2.amazonses.com[54.240.113.214]
Jan  7 16:36:58 produkcyjny: disconnect from a113-214.smtp-out.us-west-2.amazonses.com[54.240.113.214] ehlo=1 commands=1

I checked already, our servers are not DNSBL'ed anywhere, MX records are correct and the server receives mail from all other places of the Internet just fine. It's clearly something wrong in Amazon SES' setup. Can you look into it?