Ungh. This one property manager. Loses stuff on his email all the time. And by 'loses', I mean 'doesn't search'.
Everything we email out has the property name, the tenant name, and the document type in the subject line. Searching your inbox, then, is not that hard. But it's even easier just to ask everyone to resend everything when you need it.
Buddy, I'm a lawyer. I'm not your secretary. Having the lawyer do secretarial work is not cost-effective. Use the secretaries for secretarial. Better still, search your own fucking inbox.