out of office
How do I set the "out of office" feature in Mac mail?
Out of Office is typically a setting in an office where a server handles these sort of settings for computers in the local network. Mail clients on computers or mobile devices tend not to have this setting.
You can set what Apple calls "Vacation" mode for your iCloud accounts by signing into your iCloud account on the web, going to Mail, and then into your preferences. From here you can select Vacation to respond to incoming messages with a brief note about your absence.
You can do the same with Google mail (Settings > General > Out-of-Office AutoReply) and I dare say any other similar web-based email service.