Support for adding favicon by auid or from address

[dodmi]

I guess, I can start adding favicons from companies, which use external IT service providers for their newsletters by mail address? Or do you see a problem?

[lieser]

I guess, I can start adding favicons from companies, which use external IT service providers for their newsletters by mail address?

If you are talking about company a company.test, using newsletter.test to send e-mails with from e.g. foo@company.test and signed only by newsletter.test, then no.

That was not the use case for #107. I deliberately added the test that the from address is in the SDID, which prohibits this.

I still believe such e-mails should be signed by company.test, even if they are not the direct sender, but only on which behalf it is send. If they trust them to send e-mails on their behalf, they should configure DKIM accordingly that they can use a DKIM key published under the company.test domain.
This trust relationship is something I would like to avoid encoding into our internal list of favicons.

I know there are currently a few examples that contradict this a little and show an icon even if it is only signed by a *.onmicrosoft.com or *.gappssmtp.com SDID. But at least they use a separate sup-domain. And they are two very big companies, there it could be argued it is unlikely they will misbehave.
But this are exceptions I'm not really that happy with, and I would like to avoid making more.