Thunderbird just freezes for about two seconds about every fifteen seconds while typing an email. So, for instance, had I been typing this message into a new email in Thunderbird, Thunderbird would have paused three times so far while I was typing. And it doesn't only happen when writing. The problem appears to happen when TB is checking mail, or I'm clicking around into other folders, or even hitting the drop-down to check mail for a particular account. It's sporadic, and very frustrating. FYI: I am using Windows10 on a Dell Optiplex 390 (Intel i3-2100 w/ 8GB ram and 500GB SSD drive) using TB 60.0b10 (32-bit). Perhaps I should have the 64-bit version? I also notice that I have 4845 emails in the Inbox of my main account. I'm using IMAP and have two other devices checking the same box (iPhone and iPad). I do not shut my PC off at night, just the monitors, so this probably isn't TB "catching up" to what exists on the server, which is SmarterMail Enterprise 15.7. Thanks.