Do you get any error message?

What is your anti-virus software?

Can you post your Troubleshooting Information? At the top right of the Thunderbird window, click the menu button , then select Help, and then Troubleshooting Information.

The only thing that has changed is the 38.3.0 update.

It's unlikely the update has caused the problems.

I read one advice where it recommended changing the global-messages-db.sqlite to global-messages-db.sqlite.old

You'd do that when you run into problems with global search. The file has got nothing to do with problems receiving mail.

[And wow, just noticed that the new version of 'global-messages-db.sqlite' went from 9000kb at the beginning to 1000MB!

1GB sounds a lot. How big is your entire email archive?

(What is this file, anyway? Is it supposed to increase so much?)]

It's the index for the global search. When deleting or renaming the file, indexing starts from scratch, and the size of the file is growing, until the initial indexing has completed.

(I wasn't sure what uninstalling and reinstalling Thunderbird would do to all the mail that have already been downloaded. I've read it's safe, but I was still worried.)

It is safe, as the profile with all the mail is separate from the program directory.

Error console showed a long list of errors and warnings.

None of these are related to your problem receiving mail.

Unfortunately I cleared the error messages since it was so long! Most were messages, there were a few errors mentioned.

I use Norton 360. I did try disabling the email protection, but that didn't do anything to help the situation.

OK, here is a copy and paste of the troubleshooting info you asked for:

 Application Basics

   Name: Thunderbird
   Version: 38.3.0
   User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20150928051427
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (pop3) pop.iprimus.com.au:110, alwaysSTARTTLS, passwordEncrypted
     OUTGOING: smtp.iprimus.com.au:587, alwaysSTARTTLS, passwordCleartext, true

   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account3:
     INCOMING: account3, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: smtp.gmail.com:465, SSL, OAuth2, true

 Crash Reports

 Extensions
   Lightning, 4.0.3, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
   Remove Duplicate Messages (Alternate), 0.3.12, true, {a300a000-5e21-4ee0-a115-9ec8f4eaa92b}
   ImportExportTools, 3.2.4.1, false, {3ed8cc52-86fc-4613-9026-c1ef969da4c3}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 409600
     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: 38.3.0
     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.direct3d.last_used_feature_level_idx: 0
     mail.openMessageBehavior.version: 1
     mail.winsearch.enable: true
     mail.winsearch.firstRunDone: true
     mail.winsearch.global_reindex_time: 1440761539
     mailnews.database.global.datastore.id: ec237323-51fa-46b1-9787-2da65df5c4f
     mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1444046315
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true

 Graphics

     Adapter Description: Intel(R) HD Graphics 5500
     Vendor ID: 0x8086
     Device ID: 0x1616
     Adapter RAM: Unknown
     Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32
     Driver Version: 10.18.14.4112
     Driver Date: 2-2-2015
     Adapter Description (GPU #2): NVIDIA GeForce 930M
     Vendor ID (GPU #2): 0x10de
     Device ID (GPU #2): 0x1346
     Adapter RAM (GPU #2): 2048
     Adapter Drivers (GPU #2): nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um
     Driver Version (GPU #2): 9.18.13.4752
     Driver Date (GPU #2): 2-5-2015
     Direct2D Enabled: false
     DirectWrite Enabled: false (6.3.9600.17795)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: false
     GPU Accelerated Windows: 0

     AzureCanvasBackend: skia
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: cairo

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.10.8
     4.10.8

     NSS
     3.19.2 Basic ECC
     3.19.2 Basic ECC

     NSS Util
     3.19.2
     3.19.2

     NSS SSL
     3.19.2 Basic ECC
     3.19.2 Basic ECC

     NSS S/MIME
     3.19.2 Basic ECC
     3.19.2 Basic ECC

So, should I uninstall (via Windows 8.1 control panel) and reinstall an older version?

Thanks for taking the time to answer my question!

INCOMING: account1, , (pop3) pop.iprimus.com.au:110, alwaysSTARTTLS, passwordEncrypted

Unless 'passwordEncrypted' is explicitly required by your email provider, change it to 'passwordCleartext'.

This is in Account Settings - Server - Settings.

Hi,

When I went into Server Settings, there was no options for 'passwordCleartext' in the dropdown menu. My choices were: encrypted password, normal password, Kerberos/GSSAPI, NTLM, TLS certificate.

I tried the 'normal password' option, but nothing's changed.

Anyway, here are new error messages/warnings on my error console:

Timestamp: 13/10/2015 1:06:33 AM Error: An error occurred executing the cmd_getNewMessages command: [Exception... "Component returned failure code: 0x8055000a [nsIMsgIncomingServer.getNewMessages]" nsresult: "0x8055000a (<unknown>)" location: "JS frame :: chrome://messenger/content/mailWindowOverlay.js :: GetNewMsgs :: line 2719" data: no] Source File: chrome://global/content/globalOverlay.js Line: 99

Timestamp: 13/10/2015 1:13:52 AM Error: downloadable font: kern: Too large subtable., table discarded (font-family: "Open Sans" style:normal weight:normal stretch:normal src index:1) source: https://mozorg.cdn.mozilla.net/media/fonts/OpenSans-Regular-webfont.2696e36f12c5.woff Source File: https://mozorg.cdn.mozilla.net/media/css/thunderbird-start-bundle.08a09d25e7a1.css Line: 1, Column: 1057 Source Code: @font-face { font-family: "Open Sans"; font-style: normal; font-weight: normal; src: url("/media/fonts/OpenSans-Regular-webfont.83efe33660ab.eot?#iefix") format("embedded-opentype"), url("/media/fonts/OpenSans-Regular-webfont.2696e36f12c5.woff") format("woff"), url("/media/fonts/OpenSans-Regular-webfont.3cbf4d3ed22e.ttf") format("truetype"); }

Timestamp: 13/10/2015 1:13:52 AM Warning: This site makes use of a SHA-1 Certificate; it's recommended you use certificates with signature algorithms that use hash functions stronger than SHA-1. Source File: https://www.mozilla.org/en-US/thunderbird/release/start/?uri=/thunderbird/start/&locale=en-US&version=38.3.0&os=WINNT&buildid=20150928051427 Line: 0

Timestamp: 13/10/2015 1:05:31 AM Error: : Component returned failure code: 0x8055000a [nsIMsgIncomingServer.getNewMessages] Source File: chrome://messenger/content/mailWindowOverlay.js Line: 2719

Again, I'm not sure whether these messages are pointed at my IMAP or POP account.

Warning: This site makes use of a SHA-1 Certificate;

If your email provider won't replace the server cert this will bite you at some point in the future. At this time it's a warning only.

This support site seems to indicate your provider does not use any encryption. http://www.iprimus.com.au/support/technical-support/email-home/config-settings/ If that is correct, I'd look for another provider right away.

Try 'Connection security' 'None' in your server settings. Keep the 'passwordCleartext' setting.

OK, I've set the 'Connection Security' to 'None'.

I'm still trying to figure out how to set 'passwordCleartext'. I'm not seeing it as an option in the dropdown menu for 'authentication method'.

I've set it as 'Password, transmitted insecurely', which came up as an option once I set the connection security to 'none'.

Is this what you mean? (Sorry, please excuse my computer illiteracy.)

Anyway, still not receiving pop mail. The error messages now says:

Could not read chrome manifest 'file:///C:/Program%20Files%20(x86)/Mozilla%20Thunderbird/chrome.manifest'.

Could not read chrome manifest 'file:///C:/Program%20Files%20(x86)/Mozilla%20Thunderbird/extensions/%7B972ce4c6-7e08-4474-a285-3208198ce6fd%7D/chrome.manifest'.

Timestamp: 13/10/2015 10:41:35 PM Warning: Use of Mutation Events is deprecated. Use MutationObserver instead. Source File: chrome://calendar/content/widgets/calendar-widgets.xml Line: 496

Timestamp: 13/10/2015 10:41:36 PM Error: TypeError: tab is undefined Source File: chrome://messenger/content/tabmail.xml Line: 1067

Timestamp: 13/10/2015 10:41:37 PM Warning: Expected identifier for pseudo-class or pseudo-element but found '*'. Ruleset ignored due to bad selector. Source File: mailbox:///C:/Users/Judy/AppData/Roaming/Thunderbird/Profiles/27g65znu.default/Mail/pop.iprimus.com.au/Inbox?number=156277483 Line: 12, Column: 2 Source Code: v:* { behavior: url(#default#VML); display: inline-block; }

Timestamp: 13/10/2015 10:43:10 PM Error: : Component returned failure code: 0x8055000a [nsIMsgIncomingServer.getNewMessages] Source File: chrome://messenger/content/mailWindowOverlay.js Line: 2719

I'm still trying to figure out how to set 'passwordCleartext'.

This should be 'Authentication method': 'Normal password'.

I've set it as 'Password, transmitted insecurely', which came up as an option once I set the connection security to 'none'.

This should be it.

Do you get any error message other than in the error console? What actually happens when you try to retrieve mail? Have you checked about the correct server settings with your email provider?

Well, bad news is, I'm still having the same problem no matter what I do. I do get a lot of warning messages, but as I have both pop mail and IMAP mail accounts linked to Thunderbird, I'm not sure which account is generating the error/warning messages. (Some actually have my IMAP email address in the descriptor.)

I have checked my account settings, but aside from those suggested here, nothing is different to before when things were working.

When I actively tried to download from my pop mail account, these error messages showed up:

Timestamp: 18/10/2015 9:58:48 PM Error: : Component returned failure code: 0x8055000a [nsIMsgIncomingServer.getNewMessages] Source File: chrome://messenger/content/mailWindowOverlay.js Line: 2719

Timestamp: 18/10/2015 9:57:41 PM Error: An error occurred executing the cmd_getNewMessages command: [Exception... "Component returned failure code: 0x8055000a [nsIMsgIncomingServer.getNewMessages]" nsresult: "0x8055000a (<unknown>)" location: "JS frame :: chrome://messenger/content/mailWindowOverlay.js :: GetNewMsgs :: line 2719" data: no] Source File: chrome://global/content/globalOverlay.js Line: 99

Good news is my workaround (forwarding my mail to my gmail (IMAP) account, then downloading from there is working.)