As soon as they arrive from multiple accounts - usually pretty quick
As soon as they arrive from a single accounts - usually pretty quick
Within a few hours usually
A few times a day
Once a day
Every few days
Once a week or longer
I have a fax
Personal email - less and less. I do get bank and other messages sent to my email. Occasionally friends or relatives send an email especially if it is a longer message, but increasingly they use WhatsApp.
Work email - despite attempts over the years, its use has not changed. Actually, alternatives lead to more time taken as we need to go to another system to find that information, rather than just searching our email inbox.