Hi everyone,
I’ve been an enthusiastic Delta Chat user since this summer.
From what I’ve seen and understood, it’s not possible right now to communicate with regular email addresses using my Mailchat account. I fully understand the technical reasons and security considerations behind this.
From the perspective of wanting to expand Delta Chat’s user base, I see this as a hurdle. It would be ideal if, for example, I could add people to a group who don’t yet have Delta Chat but do have an email address. The major technical advantage that Delta is built on technology everyone already uses is lost.
Question for developers who are very familiar with Delta Chat: Do you see any ways to communicate securely with a Chatmail account while also communicating with traditional email addresses?
Your request seems a bit hazy, perhaps due to less precise application of terminology. Let me try to answer by guessing what you meant…
You can use the Delta Chat client with an account on both a chatmail server and a classic mailbox provider.
You can send encrypted email from the Delta Chat client to users on a classic mailbox server. The recipient can decrypt it with either Delta Chat or one of a dozen of PGP-enabled third party clients.
A user of such third party clients can use either a chatmail server or a classic mailbox server to send encrypted email to be received by either the Delta Chat client or PGP-enabled third party clients.
The Delta Chat client and publicly hosted chatmail instances default to only allowing encrypted email to combat spam. If you host a chatmail relay server yourself, you can set it up so that your account can send and receive unencrypted email.
The Delta Chat client can also send unencrypted email on both such chatmail instances and on classic mailbox servers and can also be configured to accept unencrypted email in the settings.
The only remaining question is about groups. Private groups and broadcast lists are Delta Chat features and you should not expect other clients to support it unless they specifically complete a compatible implementation, see:
If this is what you meant, you should rephrase this issue such that to request support for some kind of groups (probably separate group types for PGP-only and unencrypted messaging) that can be maintained without preserving special headers in a way that pressing Reply all in a third party client could preserve the group membership and metadata as seen by users of a Delta Chat client.
I think a similar feature was obsoleted in the past due to concerns about a member accidentally sending an unencrypted reply and possibly also quoting parts of previous encrypted messages in such a reply. Fix such errors in the source code of each third party client would be a better solution than denying even best effort compatibility. The usability as seen on third party clients would be impaired, though, as the display name of users and the group name would need to be redacted and the latter replaced with an ID for security.
Thank you very much for taking the time to answer my question!
To gain a deeper understanding, I’ll now go through this step by step. Thank you to the more technically experienced users for your patience. Discussion is a good way to test whether the features are understandable to everyone.
When I want to create a new chat in iOS, I can’t find the option to enter an email address. I can only use the QR code to add a new contact. I am overlooking this feature? Where can I enter an email address?
tl;dr do not try to interoperate with non-Delta-Chat-clients
Delta Chat uses imap/smtp under the hood. this means, that you can use chatmail relays (highly recommended). if you really need to, you can also use other imap-/smtp-servers, eg. your own, as long is you use the account exclusively for chatting.
apart from that, however, using Delta Chat to communicate with traditional email accounts is strongly discouraged since several years. even if you manage to configure thunderbird to deal with encrypted emails, you will get a lot of noise that is not hidden by thunderbird. and you would push that noise and effort to other users.
some years before - we tried to play the card “you can write to any email address”. while that obviously still sounds interesting to some, it never took off. there were too many cumbersome things. also as both, classic email provider/clients were not really moving nor had much interest.
since we focus on encryption and simpleness, we got a by far larger userbase.
finally: if you even want to process unencrypted mail with Delta Chat, please just use an app that focuses on that, as Fairmail, Thunderbird etc..
Thank you both for your assessment and for taking the time to explain the background.
I’ll keep working on sharpening my understanding of what sets Delta Chat apart from other projects, so I can collect arguments that make good communication about it possible. I had the impression that openness being able to reach anyone with an email address could be one of them. I accept that this isn’t being pursued further and will look for other arguments.
