Problems with sending mail

[sponch]

Hi, some of my Discourse Mail recipients do not get their mails (using cloudron mail, all status "green"), Just checked the events an found lots of these errors with different mail addresses. Any idea?

"message": "Upstream error: 450 4.7.25 Service unavailable, sending IPv6 address [xx:xx:........ must have reverse DNS record (S820)

edit: seems like this only happens, when the receiver uses Outlook/MS365 Mail ?! That possible?

[sponch]

guess I found the problem.
I had only configured IPV4 PTR and not V6 with my cloudron mail URL

[sponch]

mh..... still get the same error...
PTR setting Hetzner:

[jdaviescoates]

@sponch said in Problems with sending mail:

edit: seems like this only happens, when the receiver uses Outlook/MS365 Mail ?! That possible?

Yeah, I had the same problem.

@sponch said in Problems with sending mail:

guess I found the problem.
I had only configured IPV4 PTR and not V6 with my cloudron mail URL

That fixed it for me.

Although I also did this too

1. in Network: under IPv6 section I chose Public IP (was previously Disabled)
2. in Domains -> hit Sync DNS (for good measure)

Perhaps they were all needed.

If that still doesn't work look for more clues here https://forum.cloudron.io/topic/13122/email-sending-broken-after-updating-to-8-2-x-due-to-ipv6-issues/

[sponch]

working now. thx