Placing a lot of custom records today I noticed that the Record Type MX was causing a problem.
I experienced the error within the normal custom DNS updated dialog box today after also reviewing why I could not get a sendgrid sender authentication record to verify Both TXT and MX newer entries and went hunting in /home/user-data/dns/custom.yaml.
Any (TXT or CNAME) custom entries after the MX record was entered seem to no longer be verifiable yet prior custom entries still work.
Thought maybe it related to my large number of custom dns entries and cleanup I had to do here for the v .53
After Submit for a MX type custom DNS record:
Dialog box:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>500 Internal Server Error</title>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.</p>
If Custom DNS entry submit button pressed again, the record will take with OK and shows just like all other working entries:
Seems to corrupt the DNS after the bad entry and even when accepted in MiAB after submit again, the MX doesn’t register when tested externally DIG or other verify but does still show as custom dns and external dns from the application.
I’ve removed the MX custom records and have other CNAME and TXT custom records entered after that now working.
In this troubleshooting process ran ./mailinabox/tools/dns_update --force
and received a message with some dns entries (something like returned non zero values) and thus I took the 2-3 domains listed when that occurred and deleted all my custom DNS entries (after copying) and then manually re-entered and then discovered the error triggered on the MX type custom dns entry.
After removing the MX and re-adding the other CNAME and TXT entries I confirmed that Sendgrid now verified my records with the exception of the now omited MX record.