Several days ago we started seeing issues with emails being sent to our site users. Emails are not being sent on registration. When a user attempts the forgotten password functionality they get an error. We see the same error when we try the mass mailer functionality.
However, other emails to our users are being sent from our site successfully.
We are using the following:
Joomla 3.7.4
CB: 2.1.3
We have not made any configuration changes in CB. Here are our settings for registration.
And this is the error that we see on the mass mailing:
And this is the error from the forgot password functionality:
Again, other emails from Joomla system and other packages are being sent correctly, the only failures are from the CB package.
Please let me know if you have any suggestions, not being able to sign-up new users and not having the forgot password functionality is really hurting our production site.
Thank you in advance for your help.