Excessive login counts in weekly usage report

On one MAIB I configured for a client, I’ve been seeing large numbers of logins on certain accounts in the weekly usage report. In one case, it was saying there were 9,000 logins in one hour. I haven’t seen any indication of this in mail.log. Does anyone have any idea what is going on?

IMAP? Seems that IMAP clients log in constantly …

IMAP is push supported on certain clients (iPhone, Outlook, Android, etc)