Tools menu (Alt+T) > account settings > outgoing server (SMTP) > select your gmail outgoing account

Set the connection security to STARTTLS

Thanks, Matt. I made your above mentioned adjustment and I'm still getting the same error message. I tried disabling my antivirus and also made sure that Window Firewall wasn't blocking access to internet for Thunderbird. Still same error message. I've gone through the Account Settings on Gmail and Mozilla sites and everything appears to be correct. I'm stumped. Thanks in advance for all kindly assisting.

Please add the troubleshooting information to your post To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

OK, Matt, Here is the troubleshooting info. Thanks!

 Application Basics

   Name: Thunderbird
   Version: 31.7.0
   User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20150507114201
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (imap) mail.jimwilsonmastering.com:993, SSL, passwordCleartext
     OUTGOING: mail.jimwilsonmastering.com:587, plain, passwordCleartext, true

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

   account3:
     INCOMING: account3, , (imap) imap.googlemail.com:143, alwaysSTARTTLS, passwordCleartext
     OUTGOING: smtp.googlemail.com:25, plain, passwordCleartext, true

   account4:
     INCOMING: account4, , (imap) mail.yesmastering.com:993, SSL, passwordCleartext
     OUTGOING: mail.yesmastering.com:587, plain, passwordCleartext, true

 Crash Reports

 Extensions

 Important Modified Preferences

   Name: Value

     accessibility.typeaheadfind.flashBar: 0
     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: 31.7.0
     font.name.monospace.el: Consolas
     font.name.monospace.tr: Consolas
     font.name.monospace.x-baltic: Consolas
     font.name.monospace.x-central-euro: 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.tr: Calibri
     font.name.sans-serif.x-baltic: Calibri
     font.name.sans-serif.x-central-euro: 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.tr: Cambria
     font.name.serif.x-baltic: Cambria
     font.name.serif.x-central-euro: 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.tr: 14
     font.size.fixed.x-baltic: 14
     font.size.fixed.x-central-euro: 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.tr: 17
     font.size.variable.x-baltic: 17
     font.size.variable.x-central-euro: 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: a43d249b-ccb6-4358-9377-b5de966a03e
     mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     network.cookie.prefsMigrated: true
     places.database.lastMaintenance: 1435075719
     places.history.expiration.transient_current_max_pages: 104858
     places.history.expiration.transient_optimal_database_size: 167772160
     plugin.importedState: true
     plugins.update.notifyUser: true
     print.printer_Artisan_830(Network).print_bgcolor: false
     print.printer_Artisan_830(Network).print_bgimages: false
     print.printer_Artisan_830(Network).print_colorspace:
     print.printer_Artisan_830(Network).print_command:
     print.printer_Artisan_830(Network).print_downloadfonts: false
     print.printer_Artisan_830(Network).print_duplex: 1515870810
     print.printer_Artisan_830(Network).print_edge_bottom: 0
     print.printer_Artisan_830(Network).print_edge_left: 0
     print.printer_Artisan_830(Network).print_edge_right: 0
     print.printer_Artisan_830(Network).print_edge_top: 0
     print.printer_Artisan_830(Network).print_evenpages: true
     print.printer_Artisan_830(Network).print_footercenter:
     print.printer_Artisan_830(Network).print_footerleft: &PT
     print.printer_Artisan_830(Network).print_footerright: &D
     print.printer_Artisan_830(Network).print_headercenter:
     print.printer_Artisan_830(Network).print_headerleft: &T
     print.printer_Artisan_830(Network).print_headerright: &U
     print.printer_Artisan_830(Network).print_in_color: true
     print.printer_Artisan_830(Network).print_margin_bottom: 0.5
     print.printer_Artisan_830(Network).print_margin_left: 0.5
     print.printer_Artisan_830(Network).print_margin_right: 0.5
     print.printer_Artisan_830(Network).print_margin_top: 0.5
     print.printer_Artisan_830(Network).print_oddpages: true
     print.printer_Artisan_830(Network).print_orientation: 0
     print.printer_Artisan_830(Network).print_page_delay: 50
     print.printer_Artisan_830(Network).print_paper_data: 1
     print.printer_Artisan_830(Network).print_paper_height: 11.00
     print.printer_Artisan_830(Network).print_paper_name:
     print.printer_Artisan_830(Network).print_paper_size_type: 0
     print.printer_Artisan_830(Network).print_paper_size_unit: 0
     print.printer_Artisan_830(Network).print_paper_width: 8.50
     print.printer_Artisan_830(Network).print_plex_name:
     print.printer_Artisan_830(Network).print_resolution: 1515870810
     print.printer_Artisan_830(Network).print_resolution_name:
     print.printer_Artisan_830(Network).print_reversed: false
     print.printer_Artisan_830(Network).print_scaling: 1.00
     print.printer_Artisan_830(Network).print_shrink_to_fit: false
     print.printer_Artisan_830(Network).print_to_file: false
     print.printer_Artisan_830(Network).print_unwriteable_margin_bottom: 0
     print.printer_Artisan_830(Network).print_unwriteable_margin_left: 0
     print.printer_Artisan_830(Network).print_unwriteable_margin_right: 0
     print.printer_Artisan_830(Network).print_unwriteable_margin_top: 0
     security.disable_button.openCertManager: false

 Graphics

     Adapter Description: Mobile Intel(R) 965 Express Chipset Family
     Vendor ID: 0x8086
     Device ID: 0x2a02
     Adapter RAM: Unknown
     Adapter Drivers: igdumd64 igd10umd64 igdumdx32 igd10umd32
     Driver Version: 8.15.10.1930
     Driver Date: 9-23-2009
     Direct2D Enabled: Blocked for your graphics driver version.
     DirectWrite Enabled: false (6.2.9200.17292)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: false
     GPU Accelerated Windows: 1/1 Direct3D 9

     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
     4.10.6
     4.10.6

     NSS
     3.16.2.3 Basic ECC
     3.16.2.3 Basic ECC

     NSS Util
     3.16.2.3
     3.16.2.3

     NSS SSL
     3.16.2.3 Basic ECC
     3.16.2.3 Basic ECC

     NSS S/MIME
     3.16.2.3 Basic ECC
     3.16.2.3 Basic ECC

account3:

    INCOMING: account3, , (imap) imap.googlemail.com:143, alwaysSTARTTLS, passwordCleartext
    OUTGOING: smtp.googlemail.com:25, plain, passwordCleartext, true

Those settings are just plain wrong. They are also not the settings that the Thunderbird configuration wizard uses, so I have no idea how you got them.

Google provide the following configuration settings Server Name: imap.gmail.com Port: 993 Requires SSL:Yes

Outgoing Mail (SMTP) Server - Requires TLS

Server Name: smtp.gmail.com Port: 465 or 587 Requires SSL: Yes Requires authentication: Yes

So I suggest you return to the account settings and just about change everything except the server name, even though it is different.

So your SMTP settings will be Port 587 Username your full gmail email address' Authentication method Normal password Connection security STARTTLS

Note you also need to change the incoming gmail account settings to correct the port used.

Hi Matt,

Thank you for helping me with this. It's strange, but the automatic email configurator in my version of Thunderbird (31.7.0) populates the ingoing and outgoing servers as "imap.googlemail.com". I'm thinking something got buggered during a soft or hard crash. I will probably just uninstall and reinstall everything. Thanks you again. Your time and knowledge are very appreciated! Best, Jim

the automatic email configurator in my version of Thunderbird (31.7.0) populates the ingoing and outgoing servers as "imap.googlemail.com".

For the incoming server that's fine, don't change it. For the outgoing server that should be "smtp.googlemail.com".

I'm thinking something got buggered during a soft or hard crash. I will probably just uninstall and reinstall everything.

No. Reinstalling everything would be a complete waste of time.

Authentication method Normal password

In order for this to work you'd need to allow less secure apps in your Gmail account settings. Thunderbird 38 now supports OAuth2 authentication, which obsoletes the less secure apps setting. So set 'Authentication method' to 'OAuth2' for both, IMAP and SMTP servers in your Thunderbird server settings.

Thanks for your reply, Christ1. I wasn't aware of OAuth2 authentication. That's really good to know. I have found the source of my issues, and perhaps this could be addressed in a future revision of Thunderbird. I wasn't seeing the Outgoing Server (SMTP) settings in the left column of the main Account Setting window. Perhaps this heading should be a sticky at the top of the menu list, as I was oblivious to it's existence until I found an old thread in the Google Help forum. To quote the user, "The SMTP settings will not affect incoming mail. You are probably changing the wrong server settings. In Thunderbird, you need to check the SMTP server definition associated with the account, on the main Account Settings page, near the bottom. Then, select the Outgoing (SMTP) server settings, at the bottom of the left column, to check and adjust the SMTP server." Wow! Wish I seen that earlier! Thanks for all your help Matt and Christ1!

-Jim

way back here https://support.mozilla.org/en-US/questions/1068616#answer-745157 I gave you instruction that included outgoing server (SMTP) in the directions.

Hi Matt,

Hi Matt- Yes you did. But I just didn't follow your directions thoroughly. When I saw that list on the left of all of mail accounts and folders, etc., I didn't think about using the scroll bar to look beneath all of this and find an "Outgoing Mail Server Settings" field. In my opinion, it's improperly placed inside this settings dialog, which otherwise mimics the left side of the application's menu in Thunderbird (where you don't see any Outgoing Mail Server folder, if you see my point). I'm just suggesting that there might be a lot fewer confused people like me who expect the outgoing mail settings to be within each mail server submenu along with the rest of their settings. I'm still baffled by how my settings got all buggered. But I'm happy to report that all is working fine now. Thank you again for your kind assistance! -Jim

I agree about the improper placement. But I have had little luck getting my ideas into a release. What I want is a button beside the SMTP entry in the main incoming account. Somewhat like is used in Junk settings to open the global settings in Options. But years have past and we have new management, so I might try again. The three year old bug is https://bugzilla.mozilla.org/show_bug.cgi?id=781468