Server blocked at your firewall

Greetings.

​One of our mailservers - 78.129.218.28 - is blocked at your firewall (according to tests we have conducted).

It has *NO* poor reputation and it is not listed on any blacklists so far as we can see.

Since this is damaging our business (due to the inability to send legitimate emails to our contacts) we would appreciate your attention to the matter.

Thanks!