[cbsks]

You can configure fastmail to show remote images from all your contacts, but it’s all or nothing: https://www.fastmail.com/help/receive/remotecontent.html

Is this what you are asking about for mailto links? https://www.fastmail.com/help/send/openemaillinks.html

The spam filter can be customized, but I agree that it isn’t nearly as good as gmail’s. I have it configured to move messages with a score higher than 3.5 to spam which prevents all false positives for me, but 1 or 2 spam emails a week still get to my inbox. https://www.fastmail.com/help/technical/spamchecks.html#cust...

I agree that the comment manager is barebones. Fastmail does support CardDAV so you could use a different contact manager but I haven’t had the need.

Edit: I swear I am not a Fastmail shill. Just a happy customer!