I'm struggling to get a useful method of adding an image to a SOGo email
signature. The only way I've been able to reliably have an image
appear in the signature is to add a link to an externally hosted image,
which brings up security errors in Outlook and Thunderbird upon receipt.
Is there a way of doing a multi-part Mime signature similar to the way
outlook and thunderbird do things? Or do you have a recommended way of
doing something like this?