Don’t Use Rules in Apple’s Mail to Send “Out of Office” Replies
It’s helpful to unplug occasionally and ignore email while on vacation or otherwise away from your work routine. And it’s a good idea to set up a vacation auto-responder to tell correspondents what to do in your absence. It might be tempting to create such an auto-reply with a rule in Mail on the Mac but resist the temptation! It’s way too easy to end up sending replies to every message from a mailing list or to addresses that will themselves reply back causing a mail loop where each message generates another reply ad infinitum.
Instead always set up such auto-responders in the server settings for your email provider which are better about avoiding mail loops.
Here are instructions for Gmail, iCloud, Outlook.com, Spectrum, Xfinity/Comcast, and Yahoo. If you use a different email provider the instructions will likely be similar; check with your provider for details.