Alert for unread email(s)

Would be nice for owners to have a way to discover when a guest has not read certain emails.

Options would be
- report/list sent to owners daily
- add as a trigger that owners could use to email themselves
- make visible from the Ribbon (my favorite!) along with other alerts such as "unsigned rental agreements" and "not fully paid".

Maybe add a checkbox to email templates so that only certain emails can be flagged as *must read*.

I just checked my email history report filtered down to my most important "thanks for booking" and "arrival day info" emails and in both cases about 10-20% have never been read. Probably these are my problem guests who show up unprepared !

Bumping this, I just got another guest who never read any emails and is literally 20 mins from my unit.

Out of curiosity I searched email history for my welcome email and it shows 8 out of 25 never opened. I imagine in some cases that is someone with privacy cranked up, but I'd still love to know. My reaching out with a message of "just checking to be sure you got the email" will generally be viewed as my being conscientious/helpful and *sometimes* will avoid a terrible guest experience of showing up and me being unavailable.

Could a trigger be added for unread status?