Sophos Mail Manager: Denied: RDNS/HELO (HELO LP-SMTP12-01)

Hey there,

so basically I have a problem with receiving mails from our password manager provider.

The unusual thing here is that I don't get the kind of denied reasons I usually get, like when the reverse DNS is invalid or missing.

Instead I get the error message: HELO LP-SMTP12-01

Never heard of that error and couldn't find anything about it. Neither on google nor on sophos community when using the search function.

I can't set new accounts for the password manager without getting those E-Mails.

 would like to tell the provider that there seems to be something wrong with their mail server configuration.

But without a convenient error message I can't really tell them what is wrong with their server or where to lock at.

Does anybody know what the error message "HELO LP-SMTP12-01" means?

Thanks in advance.