A spammer managed to login and post a bunch of topics in my forum at https://rplstoday.com and the users tried to report them. But they get an error message, "Can't send report email". I've tried it myself and I get the same error. All other emails are going out just fine, as I receive several every day (new topic, please moderate, new private messsage, you've been mentioned, etc.).

wpForo support team, here is a thread that one of the users started (you have to be logged in to see it):  https://rplstoday.com/community/support-bug-reports/spam-report-not-working

I've also attached a screenshot of the error.

Also note that I am using SendGrid for all emails leaving the site. However, since all other emails are going out without any problems, I don't think the problem has anything to do with SendGrid.

I have checked through all the wpForo settings and couldn't find anything that might need to be changed or reviewed to solve this problem, so I'm at a loss as to what's going on.

Thanks for your help!

Update: One user stated that he tried to report using Firefox, and the message "Working" was displayed for a very long time before he gave up on it.