Is there a limit on how many recipients (Email-addresses) I can send to?

Hi, my mail app works fine testing with simple mail sending and receiving.

When I try to send a mail, however, to 80 recipients it gives me a positive feedback in the top right pop-up (mail successfully sent) but just deposits the e-mail in the outbox with (seemingly) no further action.
I do realize that also single recipient mail needs a couple of seconds, so should I just wait (let’s say 10 minutes)? Seems a bit awkward…

Thanks!

Mail-App v 1.14.1
nextcloud hub II (23.0.5)

If it is the mail app, it should show you a warning, so it’s probably not the mail app (I actually don’t know). Mailservers often limit the number of recipients per mail to prevent spam, even some of the receiving mailservers more easily tag this as spam. If you have access to the mailserver, I’d check at this point if you can see in detail what’s happening. And for multiple recipients it would be better to use mailing lists.

Thank you for the reply.
I should have mentioned that i sent the same E-Mail via Thunderbird without a Problem to the 80 recipients. Therefor I am quite positive that there is no problem with the mail Server.
Any more ideas?