There is currently an issue with delays in outbound email. This issue is caused by the email service which we rely on, which is caused by a service they rely on.
They are working on getting this fixed right now.
In the meantime you should be able to access messages on our site. Messages between users there will still be working, even while the emails are delayed.
You can monitor status here: https://status.postmarkapp.com/
We apologize for this interruption.