Emailsystem not working

Hello we have issues with our emailsystem since December 3rd. Since then the system fails to send emails regarding abstracts and as far as we can tell it doesn’t send out emails regarding accounts, for example reseting passwords at all.
I was just wondering if this is on our part or if this is a problem other people are having?

Is Celery running properly? Which Indico version are you using? Anything in the logs?