When you reach the limit of 700M messages on the Testrun server, when will the Nine Testrun server catch up to delete messages on the server? But question about this: When you chat with someone on Delta Chat, is it that the replies appear app-side, and that certain things are server-side? I am in the US and I use Delta Chat now (I communicate to people using the Testrun server). I’m still new to all Delta Chat but explain it in a simple way.
If your chatmail server quota is full, older messages will be instantly deleted server side as you receive further new messages.
If you use Delta Chat on a single device, each message is deleted instantly after your device fetches it.
If you use multiple devices, the encrypted messages will stay on the server for some time and the server will clean them up automatically. The server will remove messages larger than 200kB after a week and smaller messages after about three weeks.
Messages are end-to-end encrypted, that means neither server can read them - only you and your partner can decrypt them.
All of your content is durably stored client side on your device, so you need to back it up from time to time to retain your messages and contacts.
Not sure exactly what “certain things you mean”. Up until recently the In-Reply-To header was included plaintext, now it’s not. See Zero metadata, group descriptions, native audio/video calls and much more! - Delta Chat. Now basically almost everything is E2E-encrypted.