We have DKIM signatures enabled for a lot of domains. Most of them works correctly and can be validated without issue.
For example sending a mail to firstname.lastname@example.org validates the DKIM signing successfully.
However some customers recently reported that their DKIM signing is failing.
After some investigation I've noticed that old untouched signatures are working correctly. But for the recently enabled DKIM signing, the test fails.
To confirm this I've checked with my test domain this morning that DKIM was correctly working and it was.
Then disabled DKIM and re-enabled it (so it regenerated the keys).
Now the tests are failing for this domain and I'm not able to get it back to a working state.
Parsing the changelogs backwards I can find this in build 7719:
Changed: Generate/validate DKIM signatures now using message bytes rather than text. (Fixes potential encoding issues).
I wonder if that's the cause and would explain why previously created DKIM signatures are working and any new are failing.
Anyone else noticed an issue with (newly created) DKIM signatures post 7719 update ?