The boss’s thinking was that people who did drivebys looking for you would then email you, see your OOO, and then be able to call you to talk about whatever they were driving by for. No one liked putting their personal contact info so we never worked from home (pre-COVID and pre-VOIP implementation) or told people to IM us and we’d call them.
My OOO is almost always “I’m out of the office and will be returning on x date.” My email sig has instructions along the lines of “for questions on x, email this list” for a couple of the more common areas people would contact me about that might need an urgent reply (as the lists go to more than just me, obviously), but most people have finally figured out to contact those lists to start with, anyway. If I were in the middle of a project or something that needed to be moved along in my absence, the project teams usually know when we’re out, but I’d put a back up in that case, if needed, but generally there’s not much to be gained by a longer OOO from me.

5.) Estimados/as clientes/as, nuestras oficinas permanecerán cerradas del 24 de diciembre al 2 de enero. Podrá contactar con nosotros en horario habitual a partir del lunes 5 de enero. Le deseamos a usted y a su familia unas felices fiestas y un próspero año nuevo lleno de éxitos.
Our offices are closed until [date]. If it’s something you need urgent assistance with, contact [Name] on [phone number] or [Email] Hello! Thank you for your email. I am currently out of the office. We have closed for [holiday name]. I will be returning on [date]. If you require immediate assistance, you may reach me at – [mobile number]. Thanks!