Deltachat-android: Data privacy options

[jbacksch]

option to diable

• X-Mailer header
• UTC as default time zone

[r10s]

The X-Mailer header with the program version is present in the beta-version for debugging purposes only, it is planned to remove it in the final version, see already existing comment at https://github.com/r10s/messenger-backend/blob/master/src/mrchat.c#L1221

Using the UTC time instead of Local-time plus timezone: If this is possible, I see no reason why not to implement it in this way. However, the used standard-routine in libEtPan seems not to have an option of this point.

[rizzopablo]

I'm using the x-mailer header to filter my email from Delta and I find it very usefull, why would you remove it?

[r10s]

I do not know all e-mail-clients - is the x-mailer header really an easy-to-user criterion for filtering? I have not seen this somewhere.
As an alternative you can filter subjects starting with Chat:

Why we want to remove it? We'll for the moment, we need the version for debugging purposes, this will be less important as soon as the app is "ready". We did not though that it gets handy for other things.

A compromise may be to leave out the version number. Regarding privacy: the fact, the sender _uses_ a messaging client is also present in the X-MrMsg header which is a technical need (mails without this header do not go to the chats folder but stay in the inbox; moreover we add group-IDs to similar fields).

[aggsol]

x-mailer header also make a good criteria for training spam filters.

[rizzopablo]

I filter for the string "X-Mailer: MrMsg" cointained in any header, so the version number may or may not be present, it does not interfere the filter.

[blelop]

I use exim (server side) for most filtering operations.

[csb0730]

I think it will be necessary to have this header field available for debugging reasons any time.
From version to version there will be interferences!
Whether "X-Mailer" or "User-Agent" should be available ever.

Important!

Or am I wrong?

[r10s]

Yes, the header is very useful for debugging but it is not needed for the functionality itself. I think we can drop them if everything is almost fine - alternatively, common MTAs can remove them easily as well already today.

Regarding the Chat-* headers, which are needed for the core functionality,
I also do not think that promoting "Delta Chat" in the X-Mailer header is a big privacy issue.

[testbird]

I also do not think that promoting "Delta Chat" in the X-Mailer header is a big privacy issue.

It might rather be security related (bug/exploits).

For debuging, isn't it usually also needed to let the user copy-paste and send in the log, anyway, and that will contain the version.

[r10s]

closing this for now, i think we can continue the discussion in the new forum with a broader audience.

[aggsol]

@r10s Which forum where?!

[r10s]

@aggsol this one: https://support.delta.chat/ - it's rather new and the perfect place for discussions and feature requests :)