Is there an anti virus or a firewall here? Usually these errors fall into three categories.

1. The index of message numbers used by the server is different to the one Thunderbird has saved from previous sessions. Often because the provider has changed software on their server. This can be fixed by deleting the popstate.dat file for the account. There is one in each server folder in the mail folder in your profile.

2. Anti virus software is making an absolute hash of scanning your mail. Complaints appear to most common immediately after a version upgrade, but I have no idea why. TO solve, you may have to go as far as removing and reinstalling the anti virus or replacing it. Most have an off option, but there have been many reports over the years that using them does not solve issues with sending or receiving.

3. Firewall Software. This one is almost always immediately after an upgrade to Thunderbird or the installation. But there are exceptions. Check whatever firewall you are using to ensure Thunderbird has full internet access. Auto is not sometime sufficient. Be careful of version numbers. Thunderbird 38.4.0 is not 38.4.01 as far as most of these software firewalls are concerned.

Additionally Defender appears to require the Thunderbird process be excluded from it's supervision on some installs. Again I only have the anecdotal evidence of this forum to go by.

Thanks Matt.

I have removed everything in regards to TB. The message numbers are matching. If the isp shows 20 messages TB show it is trying to download 20 messages.

I forgot to include that I on the revert to 8.1 and the reinstall of 10 I did not reinstall my antivirus. I also disabled Defender and the firewall after the upgrade to test. That did not help.

My email was working up until I upgraded to Win10. I can not remember if it worked for the first day after the upgrade. I know that I updated TB shortly after because I could not get messages.

Thanks.

John

Looking less of a Thunderbird issue at this time. I was able to get messages from a different ISP. I also loaded Opera and wasn't able to get messages from the main ISP. Thanks for the help.

To go way back here

pop.webhost.dynadot.com responded: nding message

That is a nonsense error.

What Thunderbird is getting is nonsense, looks like the end of an error message. What errors did Opera give you?

Here is the end of the log from Opera.

6/12-2015 12:11:35 POP OUT: RETR 1

26/12-2015 12:11:35 POP IN: OK sending message

26/12-2015 12:11:35 Parse error: syntax error

26/12-2015 12:11:35 POP IN: Received: from 74.125.82.41 by webhost.dynadot.com with SMTP; 12 Dec 2015 21:18:26 +0000 Received: by wmpp66 with SMTP id p66so15508061wmp.1

       for <email cut>; Sat, 12 Dec 2015 13:18:24 -0800 (PST)

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;

       d=gmail.com; s=20120113;
       h=mime-version:date:message-id:subject:from:to:content-type;
       bh=JHiTlgVztmS/FFZnr1yfijIyREnbhYYZxmtxJdNfW4s=;
       b=fRfBULz9fkeIUmgkvXwylYLDiHpQyRPhJjMfUpMxsu6NLbHPlaFMUBMXHCj9wmOwgW
        SjbnP7v984SdUPBbDZQdwf7ZmPxFQBsA8KANJ6syNWyXB4ipRp1a2NIMWu/bToG5nlDv
        fT/79iMszgr5MgVhED+eKJB2mhP2u26nDkcHrBLUi/TrAbdbwD/RJBCMXMJz3NMWa53t
        8/tx7pe5jDY8EXu1QenUBh3+pcJvXf5qBQzoLV+8J8x5ROaRfI6n1ry96eqcb/z16V2c
        h2ufZr2pb0R5R/0QIA8liT7Prvrt+mFNqrmENrD6OD3RdeCPX5Ae1PzREjKpx2QLdnhF
        20eQ==

MIME-Version: 1.0 X-Received: by 10.28.183.198 with SMTP id h189mr13942992wmf.44.1449955104773;

Sat, 12 Dec 2015 13:18:24 -0800 (PST)

Received: by 10.28.63.88 with HTTP; Sat, 12 Dec 2015 13:18:24 -0800 (PST) Date: Sat, 12 Dec 2015 13:18:24 -0800 Message-ID: <email cut> Subject: test From: John <email cut> To: <email cut> Content-Type: multipart/alternative; boundary=001a1148eb74f5e0c70526b9fa44

--001a1148eb74f5e0c70526b9fa44 Content-Type: text/plain; charset=UTF-8

test

--001a1148eb74f5e0c70526b9fa44 Content-Type: text/html; charset=UTF-8

--001a1148eb74f5e0c70526b9fa44-- .

26/12-2015 12:11:35 Parse error: syntax error

[Repeats cut out]

26/12-2015 12:13:35 POP IN: Disconnect

Here is the latest reply from the ISP:

++++++++++++++++++++

Our engineers have run many tests and we received the following update:

After SEND: RETR 1, he gets:'

2015-12-25 01:23:07.175000 UTC - 0[1e11140]: RECV: OK sending message

But we get:

0[3411140]: RECV: +OK sending message" The difference is the '+' is missing from your log. We are not sure why that is, since we do send the response with the plus sign. For some reason, your particular environment does not get that plus sign with the response.

++++++++++++++++++++++++++++++++

My environment is Win10.

ok, lets make sure Thunderbird is not getting it either.

logs the Thunderbird connections https://wiki.mozilla.org/MailNews:Logging

Or Use telnet to actually connect to the port and type in the commands in text mode. see http://support.sasktel.com/app/answers/detail/a_id/20201/~/using-telnet-to-test-mail-server-connections-in-mac-os-x

Running telnet on my system after logging in I got a +OK.

Here is the start of the mail log.

2015-12-25 01:22:58.782000 UTC - 0[1e11140]: Setting server busy in nsPop3Protocol::LoadUrl 2015-12-25 01:22:58.860000 UTC - 0[1e11140]: Entering NET_ProcessPop3 1 2015-12-25 01:22:58.860000 UTC - 0[1e11140]: POP3: Entering state: 1 2015-12-25 01:22:58.860000 UTC - 0[1e11140]: POP3: Entering state: 2 2015-12-25 01:22:58.860000 UTC - 0[1e11140]: POP3: Entering state: 4 2015-12-25 01:22:58.860000 UTC - 0[1e11140]: RECV: (null) 2015-12-25 01:22:58.922000 UTC - 0[1e11140]: Entering NET_ProcessPop3 22 2015-12-25 01:22:58.922000 UTC - 0[1e11140]: POP3: Entering state: 4 2015-12-25 01:22:58.922000 UTC - 0[1e11140]: RECV: +OK POP3 server ready 2015-12-25 01:22:58.922000 UTC - 0[1e11140]: POP3: Entering state: 26 2015-12-25 01:22:58.922000 UTC - 0[1e11140]: SEND: AUTH

2015-12-25 01:22:58.954000 UTC - 0[1e11140]: Entering NET_ProcessPop3 1 2015-12-25 01:22:58.954000 UTC - 0[1e11140]: POP3: Entering state: 3 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: Entering NET_ProcessPop3 30 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: POP3: Entering state: 3 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: RECV: -ERR please send USER command 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: POP3: Entering state: 27 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: POP3: Entering state: 28 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: SendCapa() 2015-12-25 01:22:59.032000 UTC - 0[1e11140]: SEND: CAPA

2015-12-25 01:22:59.063000 UTC - 0[1e11140]: Entering NET_ProcessPop3 1 2015-12-25 01:22:59.063000 UTC - 0[1e11140]: POP3: Entering state: 3 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: Entering NET_ProcessPop3 30 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: POP3: Entering state: 3 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: RECV: -ERR please send USER command 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: POP3: Entering state: 29 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: POP3: Entering state: 30 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: ProcessAuth() 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: POP auth: server caps 0x4AA, pref 0x1C00, failed 0x0, avail caps 0x400 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: (GSSAPI = 0x100000, CRAM = 0x2000, APOP = 0x4000, NTLM = 0x8000, MSN = 0x10000, PLAIN = 0x1000, LOGIN = 0x800, USER/PASS = 0x400) 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: trying auth method 0x400 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: POP username 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: POP3: Entering state: 5 2015-12-25 01:22:59.141000 UTC - 0[1e11140]: OnPromptStart() 2015-12-25 01:23:06.472000 UTC - 0[1e11140]: Entering NET_ProcessPop3 0 2015-12-25 01:23:06.472000 UTC - 0[1e11140]: POP3: Entering state: 48 2015-12-25 01:23:06.472000 UTC - 0[1e11140]: SendUsername() 2015-12-25 01:23:06.472000 UTC - 0[1e11140]: USER login 2015-12-25 01:23:06.472000 UTC - 0[1e11140]: SEND: USER john@cutout

2015-12-25 01:23:06.644000 UTC - 0[1e11140]: Entering NET_ProcessPop3 1 2015-12-25 01:23:06.644000 UTC - 0[1e11140]: POP3: Entering state: 3 2015-12-25 01:23:06.722000 UTC - 0[1e11140]: Entering NET_ProcessPop3 22 2015-12-25 01:23:06.722000 UTC - 0[1e11140]: POP3: Entering state: 3 2015-12-25 01:23:06.722000 UTC - 0[1e11140]: RECV: +OK password required

Could you please copy and paste the accounts information from Troubleshooting information on the help menu.

I hope this is what you are asking for Matt. Thank you for your help.

 Application Basics

   Name: Thunderbird
   Version: 38.4.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20151119061742
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (pop3) pop.webhost.dynadot.com:110, plain, passwordCleartext
     OUTGOING: smtp.webhost.dynadot.com:1025, plain, passwordCleartext, true

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

 Crash Reports

 Extensions
   Lightning, 4.0.4.1, 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: 38.4.0
     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
     mail.openMessageBehavior.version: 1
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: d11151e3-644f-43a7-a1dc-b5b04e34047
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true

 Graphics

     Adapter Description: Intel(R) HD Graphics 4600
     Vendor ID: 0x8086
     Device ID: 0x0416
     Adapter RAM: Unknown
     Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32
     Driver Version: 10.18.15.4256
     Driver Date: 7-17-2015
     Direct2D Enabled: false
     DirectWrite Enabled: false (10.0.10586.0)
     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
     4.10.10
     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

Matt, any progress on this issue?