I find it easier to have one email address, but I have folders for each property, so that all correspondence goes into the relevant folder. I also insist on having the property address in the subject line of the email! All this works very well for me without having to log into different email accounts.
I set up a free gmail account for all my rental emails. This is also the email I use to make any online purchases for the properties & the email which i use to contact the tenants.
I do the same as Anne1 and put everything into separate folders