I've been using Thunderbird on my Mac for 15 years now. Never had any issues with it. Love it. My wife has been using it on her Mac for the last decade. Again, no issues. Two weeks ago, Thunderbird was working perfectly on both our laptops. However, overnight, we both started having issues sending emails. Any email to anyone now takes over one minute to send. It is painfully slow. Receiving emails? No problem. No problems with anything else. Only sending. Specifically, it's sending it from our Bell email accounts (we live in Canada and use Bell for our Internet needs). I have a second account using a different domain, and that one has no issues sending. Also, when I send an email using Bell's internet browser portal, it sends instantly. So there's clearly a communication issue between Thunderbird and Bell at this point. When this problem happened, Bell sent us a text telling us that our 1 GB Internet speed will now increase to 3 GB. That's when our email sending problems happened. I just spoke with Bell, and they assured me that nothing changed on their end. It's too much of a coincidence to think that they have nothing to do with this. However, after speaking with the tech, I'm wondering if for some reason Thunderbird has difficulties connecting to the 3 GB servers on Bell's end. The reason I'm suggesting this is that my laptop still shows 1 GB per second download speed. However, the modem shows 3 GB. The tech suggested that our laptops can't take in more than 1.5 GB. So it's bottlenecked on our computers' end. It's possible that Thunderbird also has a bottleneck issue because they can't negotiate the 3 GB Bell servers. In the past two weeks, I have downloaded the three different updates Thunderbird had to offer. However, we have left my wife's Thunderbird active version it when this problem started. As a comparison. No change on either system. We are both running M2 and M3 MacBook pros, so there's no chance of it being a hardware issue on this end. And again, this problem happened literally overnight. Help?