I am a delegate on my bosses email, calendar, etc. Can I change the
out of office assistant for her account?
I am not sure if being given Delegate access allows you to log directly into
the mailbox, either in a different Outlook profile or through OWA (and I
don't think it will), so you're going to need to be given Log on As (IIRC)
permissons to the mailbox to get it changed.
Depending upon the version of Exchange, you can try going to your bosses
mailbox in OWA. Just pull up your mailbox and change the URL so that it
references your bosses login rather than yours. If it lets you in, change
the OOF. If it doesn't, well, you'll want to talk to your Exchange Admin
to get it done.