Please post your Troubleshooting Information.
Help - Troubleshooting Information

Press Alt or F10 to restore the menu bar in case it's hidden.

What are the settings which were given to you, and which work on other computers?

my email address: vincent.castaignet@musicovery.com server (pop/smtp): mail.bearstech.com password: xxxxxx

Please also post your Troubleshooting Information.

Application Basics

Name: Firefox Version: 28.0 User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0

Crash Reports for the Last 3 Days

All Crash Reports

Extensions

Important Modified Preferences

browser.cache.disk.capacity: 358400 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.disk.smart_size_cached_value: 358400 browser.places.smartBookmarksVersion: 6 browser.sessionstore.upgradeBackup.latestBuildID: 20140314220517 browser.startup.homepage_override.buildID: 20140314220517 browser.startup.homepage_override.mstone: 28.0 extensions.lastAppVersion: 28.0 network.cookie.prefsMigrated: true places.history.expiration.transient_current_max_pages: 92356 plugin.disable_full_page_plugin_for_types: application/pdf privacy.sanitize.migrateFx3Prefs: true

Graphics

Adapter Description: AMD Radeon HD 8330 Adapter Drivers: aticfx64 aticfx64 aticfx64 aticfx32 aticfx32 aticfx32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64 Adapter RAM: 512 Device ID: 0x9832 Direct2D Enabled: true DirectWrite Enabled: true (6.3.9600.16384) Driver Date: 8-30-2013 Driver Version: 13.152.0.0 GPU #2 Active: false GPU Accelerated Windows: 1/1 Direct3D 10 Vendor ID: 0x1002 WebGL Renderer: Google Inc. -- ANGLE (AMD Radeon HD 8330 Direct3D9Ex vs_3_0 ps_3_0) windowLayerManagerRemote: false AzureCanvasBackend: direct2d AzureContentBackend: direct2d AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0

JavaScript

Incremental GC: true

Accessibility

Activated: false Prevent Accessibility: 0

Library Versions

NSPR Expected minimum version: 4.10.3 Version in use: 4.10.3

NSS Expected minimum version: 3.15.5 Basic ECC Version in use: 3.15.5 Basic ECC

NSSSMIME Expected minimum version: 3.15.5 Basic ECC Version in use: 3.15.5 Basic ECC

NSSSSL Expected minimum version: 3.15.5 Basic ECC Version in use: 3.15.5 Basic ECC

NSSUTIL Expected minimum version: 3.15.5 Version in use: 3.15.5

Well, I meant the Thunderbird Troubleshooting Information, not Firefox.

Isn't Thunderbird what we're talking about?

Paramètres de base de l'application

   Nom: Thunderbird
   Version: 24.4.0
   Agent utilisateur: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0
   Dossier de profil: Ouvrir le dossier correspondant

             (Lecteur local)
   Identifiant de compilation de l'application: 20140316131045
   Plugins activés: about:plugins
   Configuration de compilation: about:buildconfig
   Rapports de plantage: about:crashes
   Utilisation mémoire: about:memory

 Comptes courrier et groupes
   account1:
     INCOMING: account1, , (none) Local Folders, plain, passwordCleartext

   account2:
     INCOMING: account2, , (rss) Feeds, plain, passwordCleartext

   account3:
     INCOMING: account3, , (imap) imap.tutorielgandi.org:143, plain, passwordCleartext
     OUTGOING: mail.bearstech.com:587, plain, passwordCleartext, true

 Extensions

 Préférences modifiées importantes

   Nom: Valeur

     browser.cache.disk.capacity: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     browser.cache.disk.smart_size_cached_value: 358400
     extensions.lastAppVersion: 24.4.0
     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: 2f2912ff-56f1-43ff-9e33-00f8fdb0058
     network.cookie.prefsMigrated: true
     places.database.lastMaintenance: 1396611093
     places.history.expiration.transient_current_max_pages: 92356

 Accélération graphique

     Description de la carte: AMD Radeon HD 8330
     ID du vendeur: 0x1002
     ID du périphérique: 0x9832
     RAM de la carte: 512
     Pilotes de la carte: aticfx64 aticfx64 aticfx64 aticfx32 aticfx32 aticfx32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64
     Version du pilote: 13.152.0.0
     Date du pilote: 8-30-2013
     Direct2D activé: false
     DirectWrite activé: false (6.3.9600.16384)
     Paramètres ClearType: Paramètres ClearType introuvables
     Rendu WebGL: false
     Fenêtres avec accélération graphique: 0

     AzureCanvasBackend: skia
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: none

 JavaScript

 Ramasse-miettes incrémentiel: 1

 Accessibilité

   Activée: 0
   Empêcher l'accessibilité: 0

 Versions des bibliothèques

     Version minimale attendue
     Version utilisée

     NSPR
     4.10.2
     4.10.2

     NSS
     3.15.4 Basic ECC
     3.15.4 Basic ECC

     NSS Util
     3.15.4
     3.15.4

     NSS SSL
     3.15.4 Basic ECC
     3.15.4 Basic ECC

     NSS S/MIME
     3.15.4 Basic ECC
     3.15.4 Basic ECC

So you haven't set-up the account yet. Use Manual Setup when the wizard fails to detect the settings automatically.

https://support.mozilla.org/en-US/kb/manual-account-configuration

I did read it once, and now a second time; does not answer the problem

So what is the problem?

"Echec de l'authentification/L'identification sur le serveur" what I have mentioned at the beginning

You'd need to be a little more specific what your problem with manual account setup is, and what you don't understand from the article.

You may also ask in a French forum in case that helps.