We already changed the group message subject to Re: Group name because this is less surprising than something starting with Chat: (for when people chat with someone who does not have DC) and would like to change the normal message subject, to Re: <last subject>.
Now: What should the subject be when we send the first message to a new contact?
Letās make a poll*
Message from <sender name>0 voters
*just to get an idea of what we as community think about it, this is not the final decision
I saw in the github issues that this was potentially being incorporated. Has that been decided yet? Would love to see that change.
Welcome to the DC forum!
Im not sure if I understand your question. As group message subjects do not start with Chat: anymore, I do not think that anyone will say that private chat subjects should. But we still need to decide about the first message subject, which we try to do here.
I was referring to this 
I voted āOtherā - I find the earlier idea from your PR of having the first message subject be taken from the first few words of the content. Given that a DC peer doesnāt care about the subject line, we only care how it looks to a ānormalā e-mail user, and a normal e-mail user wants a subject that has some bearing on the content.
e.g. Alice the DC user sends a message to Bob the e-mail user, with the text:
Meet up at the park later? Make sure you're wearing a mask, maybe let Charlie know we'll be there. 5pm is fine by me.
results in the subject
Meet up at the park later?
Which is less āweirdā than
Message from Alice
as it conveys information, especially to somebody who has a dozen threads in their inbox.
One further suggestion Iād like to make is that the subject should ātime outā. If Alice the DC user is good friends with Bob the e-mail user, and Alice is often the one initiating conversations, the subject of the āthreadā will perpetually be the same thing, even weeks later. That also breaks the conventions of regular e-mail.
Iād suggest that DC āforgetsā the subject in a chat if a new message is created more than 24 hours after the last message to/from that contact. This is not perfect, but it does avoid the worst case scenario.
If s.o. else would like to vote for @rthrippletonās idea, I suggest you vote for āOtherā and like his post.
I actually know people who hit āReplyā even if the last email was months ago and the topic is something completely different, so Iām afraid I disagree with you here.
In this case, it would be lucky that the first words make a good subject but there would be many subjects like āHi Alice, I would like toā¦ā too. So Iām not sure if I agree but Iām afraid that I rather donāt.
I see your point. Bob the e-mail user e-mails Alice the DC user a few weeks later, but theyāve set a subject thatās appropriate to what theyāre talking about (because thatās how an e-mail user will normally behave), and everything is fine. Aliceās reply will be Re: Subject set by Bob.
However, Iām concerned in the other edge-case, when itās the DC user initiating a new conversation with an existing contact. Theyāre done with their āMeet up at the park later?ā conversation, and thatās the subject stored with the conversation. Two weeks later, Alice the DC user sends
You should see this hilarious video. It's a cat with a cheeseburger - that can't be healthy for it! http:// ....
and itās received by Bob the e-mail user with a āRe: Meet up at the park later?ā subject line. Alice the DC user looks like somebody whoās bad at e-mail etiquette. Itās not totally out of the bounds of normal behaviour, but it gets worse if theyāre still doing it a year later.
Yeah, that could be awkward. Iām imagining that thereād be a simple heuristic when turning the body into a subject. Keep walking the text until you have more than N words/characters, and stop on punctuation. Alice writes
Hi Bob! Has Charlie talked to you about this weekend yet? We're going to take the train to ...
which turns into a subject
Hi Bob! Has Charlie talked to you about this weekend yet?
Iām aware that I risk overcomplicating the design, but Iām fearful about DC being seen as an impolite invader into the e-mail ecosystem. Personally, I only use it for group chats with my e-mail using friends, because it appears like ānormalā e-mail with subjects. I avoid using it for 1-to-1 chats. I donāt see this ever changing, as DC will always be in a minority compared to all of the regular e-mail users out there, but thatās the idea with DC - take advantage of an existing communications system with a huge network.
BTW, I should also say that Iām very very in favour of your overall idea of having subject line not changing on each message, even if Iām quibbling about exactly what it should be 
(I donāt want to come across as 100% argumentative!)
IMHO, the short subject āmessage from Xā is fine, and also using Re: plus last subject, but in case both users have Delta Chat I would like not to send subject header at all, actually even to classic email users I would like to send the email without subject, that is still better than Chat: blah blah blah IMHO and in case of a chat message doesnāt make much sense to have subject at all, but well maybe people find it weird, I donāt because I use to send messages without subject when I am āchattingā using a classic email, who waste the time setting a subject? 