I recently added a Gmail account to Thunderbird. Before that I had four working pop3 accounts. Now two of thepop3 accounts are no longer getting new messages on this Windows 10 laptop. They work elsewhere. They can send out emails but they don't get them. The Gmail account is working. When I hit "Get Messages" the accounts no longer appear on the bottom left. If I right click on the account and choose "Get Messages" nothing happens. Thanks for you help...