Sent messages duplicated

[Zocker1999NET]

I expect that the problem is my mail provider Microsoft (@outlook.com) has something to do with this as the Microsoft Server does store every mail sent inside the "Sent" directory. I configured DeltaChat to look inside the "Sent" directory cause I do not want to have a bunch of chat mails stored there.

• Platform (android/blackberry/anbox): Android 9
• Device: Nokia 5 (European)
• Delta Chat Version: 0.304.0
• Expected behavior: Send a message to someone, expected message to show once
• Actual behavior: Message is shown twice, the message is also duplicated stored inside the "Sent" directory
• Steps to reproduce the problem: Send a message.
• Screenshots: (Can not create a screenshot now) Shows the bubble for a sent message twice with the same message
• Logs:
  sent2.log

[hpk42]

I can reproduce the problem with a fresh outlook test account. I think it's because outlook overwrites the Message-ID -- DeltaChat produces "MR..." message ids while outlook ones start with "AM" in my case.

So when DC notices a new mail it will not identify it as one that was sent out because the Message-ID is now different. Not sure how to best go about it. In any case, it's a core issue, not android, will move it.

The other issue is that outlook.com indeed appears to put smtp-outbound messages into the Sent folder automatically -- and then a second mail arrives in INBOX because of DC's "bcc-self". But the two messages have the same (outlook.com-generated) Message-ID so i think the double-message is not because of that.

[csb0730]

Can confirm this issue. No single case. Saw several occurences!

core version 0.42.0-dev, android v0.200.0
Message sent from gmx to gmx address.

I examined a message which has been sent twice.
Original send time 20:24:23

• 1st arrival at mail server 20:26:47
• 2nd arrival at mail server 22:45:37

As far as I know I was biking in an area with possibly bad network conditions.

I see a relation to the reworked handling of unstable network conditions.