Not sure how this could have happened.

This used to happen in some old releases which tried to remove a domain without a database transaction. @jegillikin-0 Do you happen to remember if you tried to delete this domain by any chance (which would have failed partially but not have given you correct feedback?)?

Many thanks for the prompt assist -- all is now well in the world.

The root cause is that this domain has not entry in the mail config database table for some unknown reason. Not sure how this could have happened.

In either case, I've manually added that db record with:

mysql -uroot -ppassword box -e "INSERT INTO mail (domain, enabled, mailFromValidation, catchAllJson, relayJson, dkimSelector, bannerJson) VALUES ('example.com', 0, 0, NULL, NULL, 'cloudron', NULL);"

and things are working now as expected. I will see how to ensure the dashboard does not break entirely when this happens.

1. No IDNs.
2. Yeah, it worked as recently as six months or so ago, which was the last time I adjusted email stuff. Then I went in around when I opened this thread and ... nothing. And still nothing, after some time elapsed and upgrades/reboots.
3. Nothing much different between InPrivate and normal browsing, nor when I disable anti-tracking plugins and allow third-party cookies on the dashboard's domain.

I'm wondering, based on those 404s, whether I need to re-provision the API key into Digital Ocean for one of those domains. Hmm.

The domain jegillikin.com does NOT have mail configured, by design -- I use Microsoft 365 for email services. It's focused on that domain even when I click the pencil icon for a different domain.

I'm currently on 6.3.4 on Ubuntu 18.04.4 LTS, and my subscription is active.

Did this work before, and now isn't? When did it stop working? do you recall if it was after adding a certain domain, or a certain email address?

You've tried different browsers... have you tried Incognito mode (that's what it is called on Chrome)? I've been able to narrow down problems by checking things out in Incognito mode (but that means you need to have the cloudron login password ready as it won't automatically log you in!).

Finally, having the web browsers Developers Tools window open while you are checking things out in both Incognito and regular mode can reveal some error messages that Cloudron's logs might not show.

It simply isn't working, and nothing in the logs explains why.

After server and Cloudron restarts, the problem persists. Email works just fine, and the email service is active and well within memory limits. I even tried a DNS resync, and a quick scan of the email logs does not suggest that anything is amiss. But when I access the Email option from the control panel menu -- regardless of the domain -- all I see is a spinning ring.

Step 1: Click the wrench of any domain:

Step 2: Get the spinny donut:

The grey- and red-dotted domains are doing what they should; one is expired and will eventually be deleted, and the other has no email service through the Cloudron instance. Everything else is green, and works -- no problems with sending and receiving. I just can't enable/disable email for a new domain or configure email on a per-domain basis.

Any insight?

What browser are you using, have you tried different ones and getting the same result?

Andy