Have you set up the account again?

What are the server settings as per your email provider instructions?

Can you post your Troubleshooting Information? At the top right of the Thunderbird window, click the menu button , then select Help > Troubleshooting Information. Press the Copy text to clipboard button and paste the information into your reply.

Yes, I tried removing the account and setting it up again but it did not help. Now I don't even get the Inbox.

The providers server settings for my "@usa.net" email use IMAP and SMTP servers on "postoffice.net", encrypted with TLS. Since the domain and server are different I usually have to set this up manually. Although the Windows 10 Mail app was able to set it up automatically. But I still much prefer the Thunderbird user interface. And it all worked with Thunderbird on my Windows 7 machine.

The Troubleshooting information is included below.

I see from that information that the IMAP server name is not correct. It should be imap.postoffice.net. I have tried to adjust that but am not able to get it to work. The SMTP server is correct.

Thank you so much for your help.

Regards, Tom

============================================

 Application Basics

   Name: Thunderbird
   Version: 38.5.1
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20151228123010
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account3:
     INCOMING: account3, , (imap) usa.net:143, alwaysSTARTTLS, passwordCleartext
     OUTGOING: smtp.postoffice.net:587, alwaysSTARTTLS, passwordCleartext, true

 Crash Reports

 Extensions
   Lightning, 4.0.5.2, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.smart_size_cached_value: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     extensions.lastAppVersion: 38.5.1
     font.name.monospace.el: Consolas
     font.name.monospace.x-cyrillic: Consolas
     font.name.monospace.x-unicode: Consolas
     font.name.monospace.x-western: Consolas
     font.name.sans-serif.el: Calibri
     font.name.sans-serif.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.sans-serif.x-western: Calibri
     font.name.serif.el: Cambria
     font.name.serif.x-cyrillic: Cambria
     font.name.serif.x-unicode: Cambria
     font.name.serif.x-western: Cambria
     font.size.fixed.el: 14
     font.size.fixed.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 14
     font.size.variable.el: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 17
     gfx.direct2d.disabled: false
     gfx.direct3d.last_used_feature_level_idx: 0
     layers.acceleration.disabled: false
     mail.openMessageBehavior.version: 1
     mail.winsearch.enable: true
     mail.winsearch.firstRunDone: true
     mail.winsearch.global_reindex_time: 1454791861
     mailnews.database.global.datastore.id: 7463ea6d-833a-45a9-9ad8-e6609376894
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1454854337
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true
     plugin.state.npican: 2
     plugin.state.npurlinterceptorplugin: 2

 Graphics

     Adapter Description: Intel(R) HD Graphics Family
     Vendor ID: 0x8086
     Device ID: 0x0a16
     Adapter RAM: Unknown
     Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32
     Driver Version: 20.19.15.4331
     Driver Date: 11-18-2015
     Direct2D Enabled: true
     DirectWrite Enabled: true (10.0.10586.0)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: false
     GPU Accelerated Windows: 1/1 Direct3D 11

     AzureCanvasBackend: direct2d 1.1
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: direct2d 1.1

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.10.10
     4.10.10

     NSS
     3.19.2.1 Basic ECC
     3.19.2.1 Basic ECC

     NSS Util
     3.19.2.1
     3.19.2.1

     NSS SSL
     3.19.2.1 Basic ECC
     3.19.2.1 Basic ECC

     NSS S/MIME
     3.19.2.1 Basic ECC
     3.19.2.1 Basic ECC

INCOMING: account3, , (imap) usa.net:143, alwaysSTARTTLS, passwordCleartext

Your combination of port and STARTTLS for the IMAP server looks unusual. There is no point speculating, your email provider knows what the correct settings are. That includes the information about which port and security is to be used. So as said before, check with your email provider.

I see from that information that the IMAP server name is not correct. It should be imap.postoffice.net.

I suppose that means you've corrected the server name.

OUTGOING: smtp.postoffice.net:587, alwaysSTARTTLS, passwordCleartext, true

Can you actually send messages with these SMTP settings?

Okay, I was able to get the IMAP server name corrected. I compared all settings from my Windows 7 machine and made sure the Windows 10 machine matched. Now it is working. And yes, the SMTP settings work.

I think it still means there is something different with the Windows 10 setup since I did not have this trouble setting up Windows 7.

Thanks again for your feedback.

I think it still means there is something different with the Windows 10 setup since I did not have this trouble setting up Windows 7.

It actually isn't rocket science. Why many people think trying arbitrary combinations of port and security is better than checking with their email provider for the correct settings is still a miracle to me.

In any case, when your problem has been fixed, can you mark the thread as 'Solved' please? Thank you.