All three issues may be related.

There may be a problem with your hard drive, with files on it for Thunderbird and your Thunderbird Profile being corrupted.

Before running the Mac "Disk Utility" to check your hard drive for problems, you should first backup your Thunderbird Profile: Profile backup.

Then run the Mac "Disk Utility" to check your hard drive for problems. I am a Windows computer tech, not Mac, so I had to look up how to do this. These two webpages will help you with this: https://support.apple.com/en-ca/HT201639 http://osxdaily.com/2012/05/24/check-hard-drive-health-mac-disk-utility/

While the utility will try to fix problems with the hard drive, your installation of Thunderbird or your Thunderbird Profile may stay broken. In that case, uninstalling then reinstalling Thunderbird will be necessary.

Before you do that, learn about Thunderbird Profiles here: Profiles - Where Thunderbird stores your messages and other user data.

You should also export some things from Thunderbird. I have created instructions to Create a clean new profile in Thunderbird and import your stuff from the old profile. They are for Windows, but most things are probably the same. Follow the first parts of the instructions for exporting things like the address books, and calendar data.

Then uninstall and reinstall Thunderbird. Like I said, I am not a Mac tech, so I don't know the best way to uninstall then reinstall Thunderbird.

Once Thunderbird is reinstalled, it may work properly. If your Thunderbird Profile is what is corrupted, or is also corrupted, then you will have to create a new Profile using the Profile Manager, then continue with my instructions for importing your stuff into the new Profile.

Thanks. I'll try these suggestions. I just noticed that I can SEND from T-bird, even with the new password, but just not Get messages. Does that tell you anything?

It tells me that you may have the wrong e-mail server settings for receiving e-mail.

You should probably use the Verizon's troubleshooter to get that info: Manage email settings and fix email issues fast with Verizon Troubleshooter.

To get to where you change the settings in Thunderbird:

Press the Alt key or F10 key on your keyboard to show the Thunderbird menu. Thunderbird menu: Tools: Account Settings: For incoming e-mail: Select "Server Settings" on the left side under your e-mail account, and the settings are on the right side. For outgoing e-mail: Select "Outgoing Server (SMTP)" on the left side, then select the server you want on the right side. Click the "Edit" button to change the settings.

No, the settings were fine. I even had Verizon share my screen and someone there checked all the settings.

T-bird just automatically started working after I started to follow your directions.

First thing I did was compact the folders, and then all the new emails that had not yet made it into T-bird appeared. I'll save your instructions for the possibility of things messing up again. Thanks for your help!