A lot of messaging systems try to reinvent the email system but many (signal, matrix, xmpp) took over one key traditional design which we actually dropped while retaining SMTP/IMAP compatibility: server-controlled identities.

With #chatmail user identities are cryptographic and reside on end user devices only. Servers are only message relays and have no control over identities or chats, only perform fast message routing. See this fosdem talk by one of our lead developers https://mirror.cyberbits.eu/fosdem/2026/ud2218a/3F9VTU-deltachat-chatmail-relays-multi-transport.av1.webm

I have a question about the #Chatmail Relay. With single device, the retrieved messages are deleted directly. So far, so good. How does multi device access work? I can't find any information on how long the messages are held or whether there is another mechanism to delete them.

@delta @adbenitez

Was thinking about the French news that they will move away from Zoom and even Signal. At first I understood the Zoom issue and was a little perplexed by the Signal one, however I can understand it in that there is no way for France to host their version. Which brings me back to a question, will XMPP make a reemergence or will something like Delta take its place? (discuss)

#xmpp #deltachat #chatmail #signal #zoom

Hi @delta
You wrote :
> With #chatmail user identities are cryptographic and reside on end user devices only

Is it similar as the solution developed by #Jami #hubzilla #simplex or #nostr ? A kind of p2p with relay network?

just hammered out a new #chatmail relay and it was relatively smooth sailing ⛵

https://chat.bitbit.software

now chatting with two neighbours 🎉 we will test it out and see how it goes...

https://chatmail.at

#deltachat

A lot of messaging systems try to reinvent the email system but many (signal, matrix, xmpp) took over one key traditional design which we actually dropped while retaining SMTP/IMAP compatibility: server-controlled identities.

With #chatmail user identities are cryptographic and reside on end user devices only. Servers are only message relays and have no control over identities or chats, only perform fast message routing. See this fosdem talk by one of our lead developers https://mirror.cyberbits.eu/fosdem/2026/ud2218a/3F9VTU-deltachat-chatmail-relays-multi-transport.av1.webm

just hammered out a new #chatmail relay and it was relatively smooth sailing ⛵

https://chat.bitbit.software

now chatting with two neighbours 🎉 we will test it out and see how it goes...

https://chatmail.at

#deltachat

Several of our teams will be at #fosdem26 ... we'll introduce our PQC and Reliable Deletion ("forward secrecy") efforts, and give an overview over multi-relay #chatmail architectures. Or catch us on the booth or some sunny place outside :)

https://delta.chat/fosdem26.html

invite link for public fosdem26 group
attention: consider joining with a dedicated conference chat profile because large public groups can attract trolls. Your private profiles are safe/unaffected then.

https://i.delta.chat/#6CBFF8FFD505C0FDEA20A66674F2916EA8FBEE99&a=invitebot%40nine.testrun.org&g=Fosdem%202026&x=AjYC5YcO-x2Uioq9ZoNPFEUh&i=oKBUjU_D2vbpSg0VP9tA23gv&s=ZfUOyrKGon_ahzU32Cej0WWw

Several of our teams will be at #fosdem26 ... we'll introduce our PQC and Reliable Deletion ("forward secrecy") efforts, and give an overview over multi-relay #chatmail architectures. Or catch us on the booth or some sunny place outside :)

https://delta.chat/fosdem26.html

invite link for public fosdem26 group
attention: consider joining with a dedicated conference chat profile because large public groups can attract trolls. Your private profiles are safe/unaffected then.

https://i.delta.chat/#6CBFF8FFD505C0FDEA20A66674F2916EA8FBEE99&a=invitebot%40nine.testrun.org&g=Fosdem%202026&x=AjYC5YcO-x2Uioq9ZoNPFEUh&i=oKBUjU_D2vbpSg0VP9tA23gv&s=ZfUOyrKGon_ahzU32Cej0WWw

on the way to #fosdem #brussels - any questions about #deltachat #chatmail #webxdc #wtf ?

you'll find part of the team, including me, at the Delta Chat booth or events - or watch out for that laptop backside 😅