This is cool, but probably not super practical. Gmail for example limits the number of messages you can send per day pretty strictly, so using it for messages would probably be unwise. Busy chats could probably eat the quota.
I see where you are coming from, but I disagree re: the practicality being limited by message sending limits.
Sister comment says Gmail allows 500 messages to be sent per day. 500 messages/day sent in napkin math = ~20 messages/hour. Per https://www.textrequest.com/blog/how-many-texts-people-send-... , American adults sent 128 or less texts per day in 2018. You can send triple that number & still not hit the Gmail limit.
For other email providers, the limit is even higher. I checked for Fastmail's equivalent daily message limits, and it enables 4,000 or more per day.
For me personally, if I'm going to be doing over ~ 50 sent messages in one day, I'm going to ditch the mobile device and move to a desktop as I prefer a full-size Model M keyboard to touchscreens wherever possible. Most of my awake time is at work or home, where desktops abound.
I don't want to speak for you or others' preferences on this, as admittedly I don't text nearly as much as most of my peers, but I suspect others also at some point reach for a desktop UI, whether native (Signal), electron (Slack), or web-based (FB Messenger / WhatsApp / pick yer poison) for in-depth, non-mobile conversations.
Based on some quick ducking (as opposed to googling), you are correct, 100-200 does appear to be the daily SMTP relay limit. I wonder if Google would raise that to, say, 500-1000 if Delta.chat started having a sizeable user market share?
My first instinct is it would likely be a hard fight. The limit is obviously a matter of preventing abuse, and changing it might change the dynamics for malicious parties or otherwise make mitigating abuse harder. This is probably an issue for most free email providers.
This is still a conceptually cool idea for many reasons, but for this and other practical reasons it may end up being preferable to use it with another email provider. Especially since I personally think JMAP is intriguing and this might be useful for Delta Chat.
I do worry that without good support for Google accounts and maybe even some other major free email providers (important: I really don't know,) Delta chat may face practical issues with gaining critical mass.
(Just for full disclosure and good practice, I am an employee at Google, but I do not work on Gmail and I'm speaking strictly as a user.)
I tend to agree with your point as shown. Every inch given to 'worthy causes' like Delta.chat can come with the cost of unscrupulous types like scammers/spammers.
I don't really expect Gmail to bend over backwards to accommodate this. Like you though, I worry that this could inhibit Delta.chat getting enough critical mass.
On the other hand, if delta.chat starts to collect some critical mass, Gmail would probably want to avoid the generation of a pro-tip like "don't use Gmail, they're too restrictive, use Fastmail/iCloud/Outlook instead" because that could cost market share...or they can increase that limit a bit and keep the status quo going well.
Full disclosure -> I am not a Google employee, but thank you for providing the caveat for your comment! Those tend to help comments be read in a more meaningful light, speaking for myself at least :D
"Sizeable" as in bigger than Google? Yeah, I guess so. Otherwise, I don't think it would care or it would make changes to Gmail's interface to try to make Delta.chat pointless for their Gmail users.
It's 500 recipients per day. That seems adequately high.
I mean, if you have a chat with 100 participants, you're limited to sending 5 messages that day, but having such big chat rooms is not really that common, is it? And if you really have that need you can get cheap account at e.g. Fastmail and increase that to 4,000 or 8,000 recipients per day.
