Multisite, ALL contact forms have stopped working

Hello,

We are running a multisite WordPress (4.8.1) with several dozen sites. Yesterday, one of our site admins reported this error message (in bold red box) after submitting:

“Failed to send your message. Please try later or contact the administrator by another method.”

I have confirmed the same behavior on the other sites as well. I updated the plugin to the most recent version (4.9) this past Monday, August 21. I have tried changing the email address to one that I know is working and get the same error, so I know it isn’t an issue with the default email address. I also emailed our server admins to check that the PHP mail feature is working. I am currently awaiting their reply as they are 12 hours ahead of me.

In the meantime, can you please offer additional ideas on how to resolve this critical issue? I’ve already read the FAQ page and looked at the WP_mail() cause, hence the email to server admins.

Thank you,
Eddie McHam

• This topic was modified 6 years, 8 months ago by eddiemcham.
• This topic was modified 6 years, 8 months ago by eddiemcham.

The page I need help with: [log in to see the link]