I had to dig a little bit to get a better view of "will this make a mess of my email if I try/test it without commitment?"; the tl;dr is basically:
(a) there is a DeltaChat subfolder in your IMAP storing the messages;
(b) the app looks for a "Chat-Version" header on emails to know to move it to (a) folder (and you can set a server side rule to also do that);
(c) a number of popular email providers (IMAP is used) are listed with some notes to help you get started: https://providers.delta.chat/; and
(d) it's using the Autocrypt/PGP standards and you can apparently import your existing PGP key if you want
It's all in the FAQ or other docs, just highlighting the things which I wanted to know straightaway before making a mess by accident just to give it a try.
(a) there is a DeltaChat subfolder in your IMAP storing the messages;
(b) the app looks for a "Chat-Version" header on emails to know to move it to (a) folder (and you can set a server side rule to also do that);
(c) a number of popular email providers (IMAP is used) are listed with some notes to help you get started: https://providers.delta.chat/; and
(d) it's using the Autocrypt/PGP standards and you can apparently import your existing PGP key if you want
It's all in the FAQ or other docs, just highlighting the things which I wanted to know straightaway before making a mess by accident just to give it a try.