I'm suddenly having difficulty sending messages to a particular set of email addresses (for my church). I get the following error message: A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server 18.104.22.168 responded with: ** email@example.com 550:administrator for help resolving this. I can send to the binsey addresses from other accounts on my computer but not from my personal email (which is a plusnet one). I can also send from the binsey accounts without any problems. This has only happened in the past 48 hours, it's been operating fine for months. The church accounts are hosted on Freeola if that's relevant. Can anyone help please?
Edit - this problem has spontaneously resolved overnight.