you must have changed a lot of defaults to manage that. Gmail has options to prevent it and Thunderbird does not default to it.

Please post the account settings shown in the Troubleshooting information on the help menu. (copy to clipboard and paste.)

Hi Matt

actually i did not change a thing. my wife has 2 gmail accounts and one of them all the mail is still n the gmail acc as well as the thunderbird? the princessmarylee one all mail has disappeared from gmail but is all in thunderbird

Still need those account configuration details.

The stuff can probably be put back, but it will be somewhat tedious.

Application Basics Name Thunderbird Version 31.6.0 User Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 Profile Folder C:\Users\Strauss Design\AppData\Roaming\Thunderbird\Profiles\t7ydhyd8.default (Local drive) Application Build ID 20150330093429 Enabled Plugins about:plugins Build Configuration about:buildconfig Memory Use about:memory Mail and News Accounts ID Name Incoming server Outgoing servers Name Connection security Authentication method Name Connection security Authentication method Default? account1 princessmarylee@gmail.com (pop3) pop.googlemail.com:995 SSL/TLS Normal password smtp.googlemail.com:465 SSL/TLS Normal password true account2 Local Folders (none) Local Folders None Normal password account3 straussdesign@gmail.com (pop3) pop.googlemail.com:995 SSL/TLS Normal password smtp.googlemail.com:465 SSL/TLS Normal password true Crash Reports Report ID Submitted

All Crash Reports Extensions Name Version Enabled ID Important Modified Preferences Name Value 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 31.6.0 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 Comic Sans MS 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 12 gfx.direct3d.last_used_feature_level_idx 0 mail.openMessageBehavior.version 1 mail.winsearch.enable true mail.winsearch.firstRunDone true mail.winsearch.global_reindex_time 1429296918 mailnews.database.global.datastore.id 5115f58b-f5e0-467d-b9a0-3152b9f81dc network.cookie.prefsMigrated true places.database.lastMaintenance 1429297071 places.history.expiration.transient_current_max_pages 104858 Graphics Adapter Description Intel(R) HD Graphics Family Vendor ID 0x8086 Device ID 0x0102 Adapter RAM Unknown Adapter Drivers igdumd64 igd10umd64 igd10umd64 igdumdx32 igd10umd32 igd10umd32 Driver Version 8.15.10.2372 Driver Date 4-15-2011 Direct2D Enabled true DirectWrite Enabled true (6.2.9200.16571) ClearType Parameters ClearType parameters not found WebGL Renderer false GPU Accelerated Windows 2/2 Direct3D 10 AzureCanvasBackend direct2d AzureSkiaAccelerated 0 AzureFallbackCanvasBackend cairo AzureContentBackend direct2d 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

ok Please c heck the all mail folder in gmail to make sure mail is actually gone.

If it is, this "should" work.

Add the princessmaylee account to Thunderbird again. This time ensure that the account is set up as IMAP. Do not touch the existing POP mail account.

Allow for any synchronization to occur. This should be quick, as the account is empty.

Now drag mail from the pop account to the IMAP account. smallish batches under about 300 work best and allow them to synchronize before you move again.

Note that holding the shift key allow you to select all mail between two mouse clicks in the mail list.