This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

I'm using Win. 10 and Thunderbird for years, Error 5.1.0 Authenticate Mail Server message on send. Using Smpt.east.cox.net no change.

more options

This problem is on my laptop only. My PC is fine and both configured the same. Both are using Win. 10 and Thunderbird for mail. The laptop receives messages fine but on sending I receive and Error message 5.1.0 Authenticate Mail Server to verify that your mail address is correct. I am connecting to smpt.east.cox.net and that is correct and the same as on my PC. I have not added or changed any service, addresses or programs. Please help as I travel with my laptop and depend on it for communication. Thanks.

This problem is on my laptop only. My PC is fine and both configured the same. Both are using Win. 10 and Thunderbird for mail. The laptop receives messages fine but on sending I receive and Error message 5.1.0 Authenticate Mail Server to verify that your mail address is correct. I am connecting to smpt.east.cox.net and that is correct and the same as on my PC. I have not added or changed any service, addresses or programs. Please help as I travel with my laptop and depend on it for communication. Thanks.

All Replies (6)

more options

Open the Thunderbird Help menu. Close click Troubleshooting Information Click Copy to Clipboard. Come back here and paste that into a reply window.

more options

Please post your Thunderbird settings for both machines.

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;
  • Clear the check box Include account names;
  • Use the button Copy to clipboard to select all;
  • Paste this in your post.
more options

First No Help window to be found or trouble shooting from that. Since I cannot send email this is my only option for a solution. bjones101@cox.net on my laptop. Same problem email will not send and I get a window saying error 5.1.0 Authenticate Mail server and verify your email address is correct. This is and the same as on my PC with the same op. syst. and addressing and it functions properly.

more options

I suggest you find the Help menu. Either.. Click the 3 bar menu button and select Help

Or

Press F10 to make the Menu Bar appear and select Help.

more options

Thanks for your patience and help. bjones101@cox.net. My PC that is working fine is using Version 45.5.1 rather than this version 45.6.0. To restate the problem: email will not send but gives an (error message 5.1.0 Authentication required Please verify your email add. is correct in your acct. settings and try again.) It is all correct.

is it possible that Win. 10 is having trouble with the version 45.6.0 ? If so help me return to the older version.


 Application Basics
   Name: Thunderbird
   Version: 45.6.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0
   Profile Folder: Show Folder
             (Local drive)
   Application Build ID: 20161222195647
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory
 Mail and News Accounts
   account1:
     INCOMING: account1, , (pop3) pop.east.cox.net:110, plain, passwordCleartext
     OUTGOING: , smtp.east.cox.net:465, SSL, none, true
   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext
 Crash Reports
 Extensions
   Lightning, 4.7.6, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
   McAfee Anti-Spam Thunderbird Extension, 2.0, false, msktbird@mcafee.com
 Important Modified Preferences
   Name: Value
     browser.cache.disk.capacity: 358400
     browser.cache.disk.filesystem_reported: 1
     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
     dom.apps.reset-permissions: true
     extensions.lastAppVersion: 45.6.0
     font.internaluseonly.changed: true
     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: 17
     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: 20
     gfx.crash-guard.glcontext.appVersion: 45.6.0
     gfx.crash-guard.glcontext.deviceID: 0x2a42
     gfx.crash-guard.glcontext.driverVersion: 8.15.10.2702
     gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle: true
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11: true
     gfx.crash-guard.status.glcontext: 2
     mail.openMessageBehavior.version: 1
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: 5f79995a-64b7-46ef-b7b9-4df4d0039e7
     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: 1485201742
     places.history.expiration.transient_current_max_pages: 79492
     places.history.expiration.transient_optimal_database_size: 127186534
     plugin.importedState: true
     plugins.update.notifyUser: true
     print.printer_Canon_MX880_series_Printer.print_bgcolor: false
     print.printer_Canon_MX880_series_Printer.print_bgimages: false
     print.printer_Canon_MX880_series_Printer.print_colorspace:
     print.printer_Canon_MX880_series_Printer.print_command:
     print.printer_Canon_MX880_series_Printer.print_downloadfonts: false
     print.printer_Canon_MX880_series_Printer.print_duplex: -1004011520
more options

If you look at the settings you posted the SMTP is set for password NONE. This should be normal password. You cannot authenticate without a password.