About a week ago, Thunderbird began running very slowly. I had my computer "cleaned up" by a local IT person, and while my computer is running better overall, Thunderbird has quit working. I can not receive or send messages consistently. I have McAfee virus software, which has never been an issue before. I deleted a majority of my emails thinking that may have been the problem, but sill no dice. I deleted and reinstalled Thunderbird, but the problem is still not resolved. Any advice? I am using Windows 10, and have a Lenovo ThinkPad Edge. Thanks in advance! Edited to add: I can send and receive emails on my cell phone no problem.