Email sending broken after updating to 8.2.x (due to IPv6 issues)
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@girish said in Email sending broken after updating to 8.2.x (due to IPv6 issues):
To fix the situation, you simply have to set IPv6 PTR record .
For me at least this hasn't worked well. I have three servers. In all three I started to get the issues. I entered a PTR record on all three servers and it checks well with google toolbox https://toolbox.googleapps.com/apps/dig/#PTR/ and with https://www.whatsmydns.net/#PTR.
The IPv6 addresses set for the PTR record are the ones indicated in the email error messages which is the same (I've just checked) than the ones indicated by curl https://ipv6.api.cloudron.io/api/v1/helper/public_ip (and the same detected in the Cloudron Network Setting if IPv6 is activated).
On one of the server I kept getting straight bounce after having set the PTR.
On the two other servers I thought the issue was solved as I wasn't getting bounce anymore but when giving a closer look I saw that some messages would still get errors like:
Delivery failure. Will retry in Xs. Upstream error: 421 4.7.23 [2a03:xxxx:xx:xxx:xxxx:7fff:fe49:51af] The IP address sending this 4.7.23 message does not have a PTR record, or the corresponding forward DNS 4.7.23 entry does not match the sending IP. To protect our users from spam, 4.7.23 mail has been temporarily rate limited. To learn more about IP 4.7.23 address requirements for sending to Gmail, visit 4.7.23 https://support.google.com/a?p=sender-guidelines-ip 4.7.23 To learn more about Gmail requirements for bulk senders, visit 4.7.23 https://support.google.com/a?p=sender-guidelines. 4fb4d7f45d1cf-5d807030e25si25472762a12.537 - gsmtp",Most would get delivered after a couple of tries by the mail server while some would stay in the retry loop indefinitely.
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Anyone else experiencing this?
One more thing. On the server where I'm still getting the straight bounce, I've tried to activate IPv6 in the Settings on Cloudron, it worked and the IP is corrected detected. However trying to install apps doesn't work anymore, it stays stuck on Waiting for DNS propagation. So it seems like something is up with the IPv6 set-up on that domain. Any clues on what I need to do? I use wildcard DNS on that domain, do I need to set-up anything manually DNS wise for that domain to work with IPv6?
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@nebulon thank you, I thought so but wasn't sure. I've done that and it first glance it seems to have solved both the app install and email bounce issue!
I'll reactivate IPv6 and try those settings on the two other servers and see if all email delivery problem also disappear.
Do I need to also create a AAAA record for the bare domain?
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@girish said in Email sending broken after updating to 8.2.x (due to IPv6 issues):
To fix the situation, you simply have to set IPv6 PTR record .
And enable IPv6 in Network settings, and then (for good measure) Sync DNS in Domains
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J joseph marked this topic as a question
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J joseph has marked this topic as solved
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@privsec could be wrong, but it doesn't look like there is anywhere for you to and rDNS/ PTR/ reverse dns record for your IPv6. I'd contact netcup support.
ah, seems you should be able to do so but they've just got a crappy unclear UI
https://helpcenter.netcup.com/en/wiki/server/network-server
I'd try whacking your mail url (my
cloudron.domain unless you've changed it) into that empty field with the disk image to the right and then clicking the diskThen check if it worked with
dig -x <your ipv6 address> +short -
@privsec you can do it. In the bottom section (i.e the IPv6 section), enter the full IPv6 address in the field on the left and the PTR record (my.yourdomain.xx) on the right, press save.
You get the full IPv6 address with the command Girish gave above (or by activating IPv6 in Cloudron settings it will show the IPv6 address automatically detected).
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@privsec yeah netcup says that but it may only takes a few minutes. You can check your PTR record propagated in various ways, for example:
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