Also, when I forward an email, the same image is added. Attached is a screen shot of the email problem with my image on the right-hand side.

what add-ons are you using? particularly conversations? or address management?

I'm not sure how to find out everything you asked. But I can tell you that there are 1. no extensions used 2. Appearance: only the Default 24.6.0 3. Plugins: Adobe Acrobat 11.0.9.29, Citrix Online Web Deployment Plugin 1.0.0.104 Microsoft Office 2010 14.0.4761.1000 Microsoft Office 2010 14.0.4730.1010 There are 3 others which have been disabled (Nitro PDF plugin, Photo Gallery, VLC Web plugin) I don't know how to answer your query about the conversations and I only have one email address. The frustrating thing is that this photo (which I know but I'm not sure where on my computer it's stored) must be set somewhere to be attached to each of my emails.

Please copy to clipboard and paste into a message here the information on the Troubleshooting information on the help menu,

Application Basics

   Name: Thunderbird
   Version: 24.6.0
   User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20140610001341
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Crash Reports: about:crashes
   Memory Use: about:memory

 Mail and News Accounts
   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account3:
     INCOMING: account3, , (pop3) mail.optusnet.com.au:110, plain, passwordCleartext
     OUTGOING: mail.optusnet.com.au:25, plain, passwordCleartext, true

 Extensions

 Important Modified Preferences

   Name: Value

     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: 24.6.0
     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: 3c0e414b-2dab-4ccf-8897-8cf567930c4
     network.cookie.prefsMigrated: true
     network.online: false
     places.database.lastMaintenance: 1412293568
     places.history.expiration.transient_current_max_pages: 92439
     plugin.importedState: true
     plugin.state.npnitromozilla: 0
     plugin.state.npvlc: 0
     plugin.state.npwlpg: 0

 Graphics

     Adapter Description: AMD Radeon HD 7500G
     Vendor ID: 0x1002
     Device ID: 0x990a
     Adapter RAM: 512
     Adapter Drivers: aticfx64 aticfx64 aticfx64 aticfx32 aticfx32 aticfx32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64
     Driver Version: 13.251.9001.0
     Driver Date: 4-23-2014
     Direct2D Enabled: false
     DirectWrite Enabled: false (6.3.9600.17111)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: false
     GPU Accelerated Windows: 0

     AzureCanvasBackend: skia
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: none

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 1
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     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