The reason I was wanting to use a different address is to try and avoid receiving a bunch of out-of-office replies to my regular mailbox. I’m assuming out-of-office replies go to the From address and not the Reply-To address, but I might be mistaken on this.
Regardless, I’m probably best to just try sending from my regular mailbox and see what the impact is. If I get thousands of out-of-office replies then I can look at another way to manage it. I could possibly set up a filtering rule to remove anything with out-of-office in the subject which might help to reduce the impact.