I sometimes wish to find emails that I couldn't have known I would need again. Right now, I've been looking for the email address of the landlord of the house

I sometimes wish to find emails that I couldn't have known I would need again. Right now, I've been looking for the email address of the landlord of the house I lived in until 2009. I'm happy that I didn't remove his email saying that his son would come on Friday to fix the door handle.