MailCow is rejecting every e-mail...

Shadow

I’ve setup a fresh installation of MailCow. I’ve followed all the steps described here: https://mailcow.github.io/mailcow-dockerized-docs/ .

I’ve seutp a domain inside the server, created a mailbox and configured all the DNS settings accordingly. Upon testing I see that MailCow is rejecting every external incoming e-mail. I can’t find anything in the documentations how to fix this…

diekuh

I see one inbound and one outbound mail.

I also see ARC and DKIM rejects. Perhaps something changes the mail. Don’t know, not happening normally… 😉

Shadow

Anyone else can provide a more useful response?

Gebemsea

Just in case… can I ask, have you updated to the very latest build of Mailcow? Perhaps give that a try? There was a build a couple of weeks ago where some of the default rSpamd setting were too sensitive. It was fixed (as always 🙂) very quickly. Maybe not your issue, but worth a try to run the update.sh script?

Shadow

pkernstock Well it’s a fact that after doing an update as Gebemsea suggested the issue was solved. If there was a real DKIM problem on the O365 mailsystem of a major worldwide insurance company than I would have heard the noise from there. 🙂

Also e-mails from Gmail got rejected.

Shadow

I downloaded and installed this mailcow a week ago. So I would assume I have the latest Rspamd version. But to be sure I will try to update it because it sounds indeed similar in regards of beeing way to sensitive….

pkernstock

I don’t believe that updating might change the situation here. Based on the rspamd check “R_DKIM_REJECT” I’d assume the DKIM is wrong - either (as @diekuh said) the email is changed or because the DKIM key is wrong or not set correctly.

Based on the lack of further details, I guess the email was sent from “xx.onmicrosoft.com” to the mailcow-hosted mail instance? If so, I’d guess the DKIM of the xx.onmicrosoft.com domain is wrong.

diekuh

It does indeed look like mail from MS was DKIM invalid which I doubt. Something is very fishy. You also seem to have other issues with the setup, something is really broken.

pkernstock

When mails from different providers got rejected due to invalid DKIM, it could be as well a DNS issue. Because DKIM depends on DNS working. Glad to hear that updating worked, but DKIM is working within the mailcow setup when everything is correctly set up - we would have noticed, when there would be a general issue way sooner.

Just to clarify: The rebalancing does indeed changing the weights for each rspamd symbol, but it’s not changing how DKIM works or what is classified as “rejected”.

In other words: If DKIM is wrong and gets negatively scored, it still get’s negatively scored - but just less. So the “is wrong” is now “is less wrong”. You can check the commit yourself: mailcow/mailcow-dockerizedfa153fa. “R_DKIM_REJECT” was increased from score of 10 to 8.

So two possibilities:

The email just get less negatively scored (below the reject threshold).
The restart fixed something, and not the changes itself.