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! For two reasons:
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. And second, the rule only works while the computer is running and connected to the internet with the Mail app open. If your computer is turned off or crashes partway through your vacation the autoresponder will stop.
Instead, always set up such auto-responders in the server settings for your email provider, which are better about avoiding mail loops and will continue working even when your computer is offline. 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.