Stop guessing at server settings and get the correct settings from your provider. They configure their servers so they should know the correct ones to use. You could also say who your provider is so someone here has something to work with. Better yet post your Thunderbird troubleshooting info here. Go to the Help Menu and select Troubleshooting Information Click Copy to Clipboard and paste that info into a reply window here on the forum.

Application Basics

   Name: Thunderbird
   Version: 52.7.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0
   Profile Folder: Open Folder

             (Local drive)
   Application Build ID: 20180322145026
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory
   Profiles: about:profiles

 Mail and News Accounts
   account1:
     INCOMING: account1, , (pop3) mail.madasafish.com:110, plain, passwordCleartext
     OUTGOING: , smtp.madasafish.com:587, plain, passwordCleartext, true

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

 Crash Reports

 Extensions
   ImportExportTools, 3.3.0, true, {3ed8cc52-86fc-4613-9026-c1ef969da4c3}
   Lightning, 5.4.7, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.filesystem_reported: 1
     browser.zoom.full: true
     extensions.lastAppVersion: 52.7.0
     font.internaluseonly.changed: false
     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: f484e8d3-a539-4ffb-8f6e-a3d819b0a26
     mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     mailnews.database.global.views.global.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     media.gmp.storage.version.observed: 1
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1524761496
     places.history.expiration.transient_current_max_pages: 122334
     print.printer_Canon_MX920_series_Printer.print_bgcolor: false
     print.printer_Canon_MX920_series_Printer.print_bgimages: false
     print.printer_Canon_MX920_series_Printer.print_duplex: -437918235
     print.printer_Canon_MX920_series_Printer.print_edge_bottom: 0
     print.printer_Canon_MX920_series_Printer.print_edge_left: 0
     print.printer_Canon_MX920_series_Printer.print_edge_right: 0
     print.printer_Canon_MX920_series_Printer.print_edge_top: 0
     print.printer_Canon_MX920_series_Printer.print_evenpages: true
     print.printer_Canon_MX920_series_Printer.print_footercenter:
     print.printer_Canon_MX920_series_Printer.print_footerleft: &PT
     print.printer_Canon_MX920_series_Printer.print_footerright: &D
     print.printer_Canon_MX920_series_Printer.print_headercenter:
     print.printer_Canon_MX920_series_Printer.print_headerleft: &T
     print.printer_Canon_MX920_series_Printer.print_headerright: &U
     print.printer_Canon_MX920_series_Printer.print_in_color: true
     print.printer_Canon_MX920_series_Printer.print_margin_bottom: 0.5
     print.printer_Canon_MX920_series_Printer.print_margin_left: 0.5
     print.printer_Canon_MX920_series_Printer.print_margin_right: 0.5
     print.printer_Canon_MX920_series_Printer.print_margin_top: 0.5
     print.printer_Canon_MX920_series_Printer.print_oddpages: true
     print.printer_Canon_MX920_series_Printer.print_orientation: 0
     print.printer_Canon_MX920_series_Printer.print_page_delay: 50
     print.printer_Canon_MX920_series_Printer.print_paper_data: 9
     print.printer_Canon_MX920_series_Printer.print_paper_height: -1.00
     print.printer_Canon_MX920_series_Printer.print_paper_name:
     print.printer_Canon_MX920_series_Printer.print_paper_size_unit: 1
     print.printer_Canon_MX920_series_Printer.print_paper_width: -1.00
     print.printer_Canon_MX920_series_Printer.print_resolution: 600
     print.printer_Canon_MX920_series_Printer.print_reversed: false
     print.printer_Canon_MX920_series_Printer.print_scaling: 0.80
     print.printer_Canon_MX920_series_Printer.print_shrink_to_fit: false
     print.printer_Canon_MX920_series_Printer.print_to_file: false
     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_bottom: 0
     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_left: 0
     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_right: 0
     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_top: 0
     security.sandbox.content.tempDirSuffix: {200febeb-e221-4a8f-b721-70f96202468b}

 Graphics

     GPU #1
     Description: Intel(R) HD Graphics 620
     Vendor ID: 0x8086
     Device ID: 0x5916
     RAM: Unknown
     Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32
     Driver Version: 23.20.16.4849
     Driver Date: 10-27-2017

     Features
     Direct2D: false
     DirectWrite: true (10.0.16299.15)
     WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 620 Direct3D9Ex vs_3_0 ps_3_0) -- OpenGL ES 2.0 (ANGLE 2.1.0.2a250c8a0e15)

     AzureCanvasBackend: skia
     AzureCanvasAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: skia

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.13.1
     4.13.1

     NSS
     3.28.6
     3.28.6

     NSS Util
     3.28.6
     3.28.6

     NSS SSL
     3.28.6
     3.28.6

     NSS S/MIME
     3.28.6
     3.28.6

OUTGOING: , smtp.madasafish.com:587, plain, passwordCleartext, true

This doesn't look right. Try port 25 instead of 587. Also the outgoing server name may not be correct. You should confirm the outgoing server settings with your email provider.

I haven't found any evidence that they do support secure connections to the server. If I were you, I'd find a new email provider ASAP.

I have tried port 25 and no luck and have confirmed the settings with the ISP provider used for 20 years.

I have ... confirmed the settings with the ISP provider used for 20 years.

Please post the confirmed settings here.

outgoing server smtp.madasafish.com port 587 incoming which is fine: mail.madasafish.com POP

That contradicts what they publish on their web site. http://www.madasafish.com/support/email/setup/settings/windows_mail_check_settings.shtml

Whether the information on the web site is still correct, I don't know. Hence the question to confirm the settings with your email provider.

I'm afraid you'll have to sort this out with them.

I have laready spoken with the provider who co nfirmed that I had the correct settings before i replied to your email earlier. Thanks

If you have confirmed your settings why are you using smtp.madasfish.com instead of mail.madsafish.com for your outgoing server like their website says?

When your problem is fixed, can you mark the topic as 'Solved' please? Thank you.