Hi,
It might be useful if zammad had a proxy server and rewrote external links found in emails and whatnot to load via it. So if an email had an image embedded in it with a url of http://somecompany.com/signatures/bob.downe.png, zammad would rewrite the url in the html it sends to agents to https://myzammadserver.com/proxy?http%3A%2F%2Fsomecompany.com%2Fsignatures%2Fbob.downe.png
That would fix browsers complaining about the page not being secure and also hide from customers the ip address of agents.
bonus points if the “raw” link shows the original text without the rewrite.