Received message from different SMTP server (554 Blacklisted [178.248.62.3]; please try again later or contact administrator)

[R.B]

Hello, when I was testing Server connection diagnostics, an error message appeared on Port 25 / Port 587: Received message from different SMTP server (554 Blacklisted [178.248.62.3]; please try again later or contact administrator).
Version information: Version 2.4.5 PRO # 2719

How can I solve this problem?
Thank you!

[SH]

It's a sort of OK response - it tests if our server can connect to yours, but if you run tests often, our system's IP address will end up on the blacklist like any other host that doesn't produce valid email.

Just go to "Blacklist / Whitelist" -> "Automatically generated" -> search for "178.248.62.3" and hit delete, then everything should work as usual. Or just wait for the item to expire...