Rated 5 out of 5 stars

Excellent add-on. Performs as advertised, starts working at once, and quite fascinating to review one's mail and see who has got their DKIM/DMARC config wrong. Including me, in the first instance.

Cheeky suggestion: If Philippe Lieser is looking for something to do in his copious free time, may I suggest he consider adding BIMI logo display to the add-on? At the moment I believe it displays logos of well-known senders from its own private collection of icons. To load the correct logo dynamically would be even cooler.

This review is for a previous version of the add-on (4.1.1). 

Regarding BIMI and the potential problems and benefit of using it see https://github.com/lieser/dkim_verifier/issues/242#issuecomment-788283783.

For now you unfortunately have to create an issue/PR or write an email to add an icon missing in the internal list.