Hetzner PTR Record Invalid

[Dave Swift]

Hello,

I’m running Cloudron on a Hetzner server and have been using it as a mail server for about a year with no issues.

Starting yesterday, my PTR record began showing as invalid on tools like MXToolbox and WhatsMyDNS. Since then, all outgoing mail has been rejected by recipients, with the failure message indicating that the PTR record is not configured correctly.

Everything appears fine in the Cloudron dashboard (green checkmark next to the PTR record), and nothing has changed on my Hetzner server configuration.

I’ve already opened a ticket with Hetzner to investigate, but I’m curious if anyone else is experiencing this issue or has insights into what might be causing it.

Thanks for any help you can provide!

[scooke]

The green checkmark could just be the result read from a cache. When I hit these kinds of issues (not necessarily network issues, just "the settings are right, but it isn't working"), I re-enter them and resave them as though they aren't right. And, reboot the server. Duration of "no issues" is not the benchmark for "is it working". Let us know what the problem was - I bet it is something on Hetzner's side.

[Dave Swift]

Of note -- The only thing that did change Cloudron related, is updating to v8.2.0 and, just now v8.2.1, which I know included some updates to Haraka.

[girish]

@Dave-Swift The PTR record comes from Hetzner and it's not possible for Cloudron to change it even if it wanted to (i.e PTR record is unrelated to your domain). See https://docs.cloudron.io/email/#ptr-record

[Dave Swift]

Never mentioned Cloudron changing it.

Mail is failing after last update. PTR record is in tact and correct.

[jdaviescoates]

@Dave-Swift said in Hetzner PTR Record Invalid:

PTR record is in tact and correct.

@Dave-Swift said in Hetzner PTR Record Invalid:

PTR record began showing as invalid on tools like MXToolbox and WhatsMyDNS. Since then, all outgoing mail has been rejected by recipients, with the failure message indicating that the PTR record is not configured correctly.

I wonder if it's these tools that are failing/ getting it wrong. I note the I seem unable to check DNS or rDNS stuff on Hetzner using MXToolbox recently. Perhaps Hetzner are blocking it at their end or something.

Could be that your mails getting undelivered is unrelated. Are you on Hetzner Cloud? Have you checked if you're on spam blacklists? In the past I've ended up on blacklists because I was in the same range of spammers.

[girish]

@Dave-Swift I was merely removing Cloudron out of the list of suspects

You probably did this, but have you tried host -t PTR <ip> already? For example, host -t PTR 45.55.2.141 returns my.cloudron.io . This helps figuring if it's the tools at fault or if the entry itself is wrong. If entry itself is wrong, only Hetzner can fix this since they own the IP and thus the DNS space for the reverse.