Love how there was no answer to this, it's like no one cares about this forum.
The issue was you have to enable PHPMailer and set the encryption method correctly in website/core/email.php
There is also the possibility you would have to add a new configuraion to website/core/classes/Email.php
You just delete the text in that and replace it with this https://gist.githubusercontent.com/samerton/a26df55561f9735eb2f69af6868f57fb/raw/39600339f889e35546daa8a7f9b89788cfa73261/Email.php
It would by much better if the error wasn't just Error Unknown but something like Error Unkown - Possible Misconfiguration
I just had tunnel vision since in xenforo you have to disable the php mailer to use smtp. With this you require the php mailer enabled in addition to the smtp details.
Such a simple fix, upsetting it took 3 days for a support person / developer to even respond. Turns out they didn't even fix the issue, it was just me realising that i did something dumb on the last picture I sent them
https://github.com/NamelessMC/Nameless/blob/9c158cc793df678815dee34daaaed2b0a1a636cc/core/classes/Email.php#L45 This is the code that handles the error.
Just found the discord server in github, why not have it listed on the main website
This is such a pain, my SMTP server works everywhere else. And when I go to view logs I can't find where to see them. The only place I see is going into maintenance debug mode, and still there is no log. Even researching this, there is barely any information I can find on google for how I can figure out what the problem is, and there isn't even a discord server. So no I have to wait for someone to replay to this forum post, and the last reply was 20 days ago from someone saying they have the same issue.
There should be a dedicate place for viewing everything that's going on on the site, all incoming and outgoing connection information, every time someone tries to log in with their details and all changes made to the website by the specific user. These logs shouldn't be able to be deleted in the website, and it should be CLEARLY labelled when using the software, like a folder in the main directory called logs, or even logging into the system logs like everything else does.
This is so dumb.