Two more advantages of using Chatmail accounts:
- In the case you use -for your classic email- a classic email client with notifications, that classic email client won’t bother you with unnecessary notifications of Delta Chat messages.
- You won’t receive unencrypted classic emails on Delta Chat. This confusing thing can be solved by manually setting the “Chats Only” option as unfortunately this is not the default option by now.
Regarding advantages of using an existing email address, I can think of:
- Everyone who knows your email address knows your Delta Chat address
- You can quickly start a Delta Chat conversation without using any QR or link, you just need the recipient’s email address (I think this is not possible with Chatmail accounts as they require P2P-encrypted communications since the very first message).
When starting a Delta Chat conversation with existing email addresses (without using any QR or link exchange), your first message will be unencrypted, but it will automatically include your public key, so the recipient’s answer will already be encrypted with your public key. They will also include their public key in their first answer so the 2-way P2P communications gets established. So the only unencrypted message would be the first one and, without exchanging or configuring anything, P2P communications will automatically take place. However, in order to avoid potential Person In The Middle attacks, both sides should manually verify their keys (fingerprints on “Encryption Info”) through a secure parallel channel.
So, when in a hurry, using existing email addresses lets you quickly start deltachatting and then later at some time do the key verification.