No acces at all in forum

[m13]

Hello! I hope you are fine.
I am looking for help, because since today morning we lost the access to the forum.
Very few users have access. But most of them dont, neither the admins, even in the admincp.
We tried to reset the passwords, but the forum is not sending the email. We tried to create new users, but it does not send the confirmation email neither.
So we cant reset the admincp by changing the file tools.php.
We also tried to change the password in the user database, but it did no work either
Yesterday was a maintenance perform by the server, but they said that was just a firmware update, and that does not affect the software.
If someone has any idea how to solve this problem, I will appreciate it very much.

Thanks!