Schedule / Delay Email via Outlook for Mac

I have a 2018 Macbook Pro 13" running High Sierra 10.13.6. I'm running Outlook for Mac installed by my employer (university). I like to schedule emails I do at night/weekends for later weekday delivery (rather than annoy colleagues!).

The Mac version of Outlook does not have this feature (at least in the Exchange server version being run here). I used Boomerang at my last employer but it would not download and got an error message of "REST AP is not yet supported for this mailbox." Our campus IT support told me "Boomerang is dependent on a later version of the Exchange server than what we are running" which he told me is "2010 SP3"

Can anyone help? Is there an alternative out there that would work with this and allow me to schedule when emails go? Thanks.