Support for non-chatmail email

@Minim: Thanks for bringing up UnifiedPush. In my case, Delta Chat is
actually the only app on my phone that could possibly benefit from push
notifications; so using IMAP IDLE (as is the current state) works great
for me. But maybe this will be useful for others.

@Raiden: Thanks for posting that link. I was actually referring to a
different one, but that one is also interesting.

I myself am actually quite happy with Delta Chat pushing end-to-end
encryption. I am more concerned with the fact that I seem to get less
end-to-end encryption after the v2.x update instead of more. This
is partially related to the fact that Autocrypt does not seem to
work properly any more. And also because the strong split between
purely end-to-end encrypted chats and purely non-e2ee chats means that
conversations with certain peers are duplicated (and thus downgraded)
as soon as those peers send a single non-e2ee message. Previously, I
was – for a rather short time – able to reply to non-e2ee messages
using end-to-end encryption; and I rather liked that.

@link2xt: Thanks for explaining where to open which kind of issue. I
was indeed a little at a loss as to where I should open issues. I have
now reopened the issues I mentioned earlier either in the bug tracker
for Delta Chat core

or in the forum

Thanks for your help. I hope that these issues will generate fruitful
discussion.