I noticed that I didn't receive any reply notifications from the forum. Our IT tracked down the issue to our firewall rejecting these mails with the message "RDNS missing". The firewall checks RDNS entries and didn't find one for 213.197.219.229 (the server sending these e-mails).

They added an exception for notused@llblgen.com, but I thought you might want to know.

Hmmm. the emails are sent through our ISP (is.nl) which hosts our servers. Strange that the server doesn't have a DNS entry, it indeed fails.

I'll ask them if that's by design and what to do. Thanks for the heads up!

The IP address is our own server, and indeed no PTR record is available. We've asked our ISP to add one if possible, but that likely will take a few days, if they're doing that.

Should work now