I see there is also a complaint at reddit about a potentially similar problem. https://www.reddit.com/r/gamedev/comments/1boc27x/opengameart_doesnt_sen... I wonder if anyone could have look into the issue?

Added a warning on the registration page. See image below. Verbiage suggestions welcome. Hopefully this will serve as a stop-gap for now. I can always rename your nick to the one you really wanted in the event it becomes unaccessible due to this issue.

EDIT: Issue is fixed, warning removed from registration page.

Also, @dejonge2 there isn't really a reason you won't be able to post here again. You can log in with your username and the password you picked. You won't be able to change your password nor get any notifications via email because of the temporary email used, but that doesn't stop you from logging in now that you're registered.

Wow this is a weird issue. MedicineStorm, what kind of framework is this thing running on? I don't really see why it'd be _that_ difficult to support using TLS, unless you're just using really outdated servers installations.

Can't deny its incredibly annoying that Gmail keeps changing its requirements though. I've had to go through these things many times at work as well...

"...unless you're just using really outdated servers installations..."

Bingo. Well, maybe not outdated server hardware/OS, but the OGA framework is drupal 7. The current drupal version available is 10.2. There is no upgrade path from 7 to current, and certainly no simple update with the massive database and custom modules. TLS 1.3 didn't exist when drupal 7 was built, much less the consideration to incorporate it into drupal's emailing system.

Ah its Drupal. Been a long time since I worked with Drupal. Still, I'm sure it could probably be worked around without having to rely exclusively on upgrading Drupal.

I was wondering if maybe the problem was your PHP version (assuming you used PHP, I wasn't sure if it was PHP or something else perhaps like ASP/PERL/Python, which I have less experience in).

That's probably in there as well. Upgrading PHP would enable TSL stuff, but it would also break EVERYTHING else until we get the rest of it updated. Also, yes we're aiming for an OGA that isn't neccessarily Drupal at all. More of a replacement + migrate data than an upgrade. 

Well that's why I was bringing up server-side stuff lol. What I meant is:

Is this issue caused by PHP (which would be much harder to resolve), or is it caused by the software version you're using being outdated?

Because as long as your server environment (PHP, etc) supports TLS, it probably wouldn't be too hard to replace Drupal's internal mail functionality with something more up-to-date without fully upgrading Drupal. But if its literally not supported by the servers at all, that cannot be avoided.

What I meant was, the difficulty lies in the entanglement of outdated framework needing outdated PHP. There is nothing I am aware of about the server hardware/OS that prevents modern PHP versions from being used, but this statement...

"it probably wouldn't be too hard to replace Drupal's internal mail functionality with something more up-to-date without fully upgrading Drupal."

... is incorrect, unfortunately. Modern PHP breaks nearly every part of drupal 7 and the modules it uses. It is filled with deprecated functions and now-forbidden datatype uses. Replacing just the mail functionality would still leave every other part of the site busted. We can't tell the mail functionality to use PHP 7+, but tell everything else to keep using PHP 5. Which means all parts of the site have to be overhauled to work with modern PHP, or the whole site has to keep using outdated PHP.

Right, that's what I was confirming. If its PHP that's the cause then yeah there's nothing you can do about that, you have to upgrade the software first. I know you can't run different versions of PHP for different aspects of a server.

My company is trying to upgrade PHP as well to a newer version but in the process we have to upgrade the entire codebase as well. Its definitely a pain, but even more of a pain for a non-profit website.

Ouch! So you definitely are familiar with this pain. I would like to say "come help! We need your skills", but I doubt you want to do more of your day job as hobby volunteer work. Death's Darling (aka ElizaWy) is making some pretty big strides on a replacement OGA framework (PHP, but not Drupal), so if you are interested, we'll meet up and talk about next steps. No pressure though.

I'd love to help where possible, but yeah my time is rather limited right now. Still, PHP/JS web development is literally my day job so I know a lot about this stuff. I literally work with email all the time as well (sending email, grabbing email via IMAP, using Google and Microsoft's API's to get/send email, etc), which is why I brought it up.

Drupal specifically I have limited experience in, but I know PHP in general so it wouldn't be too hard to pick up. But a new framework is probably better at this time.

Just sucks there's no "easy solution" to this email problem.

Gmail issue is fixed. Botanic and Bart were able to get the records in for an alternative auth. I tested a registration with gmail and got the registration email right away. Please let me know if others are still experiencing issues.