
Password changed in BT. Tbird does not demand new password
Have removed password entry in security. Tbird then hangs on 'Connected to ....', but does not offer chance to put in new password. So I can see inbox and emails on BT but not through Thunderbird. Solutions appreciated.
Tom Nicholson
Chosen solution
tomnik said
Thanks, Matt, but I have been failing for some time to get to the F5 version of Safe Mode; that button just gives me the unhelpful version without networking.
Do you have a wired connection? wifi drivers usually will not load in safe mode.
Read this answer in context 👍 1All Replies (20)
In Thunderbird go to Options-Security-Passwords-Saved Passwords Click Show Passwords Right click the password and select Edit.
Password not there to edit - on advice, i removed the entry in order to prompt Thunderbird to ask for new password - it didn't
Usual cause here is an anti virus product that has a password "vault" or a product like lastpass, but I would expect you should know if you have installed a password manager. So I would be looking at the anti virus product.
Thanks, but no password manager, and temp turn-off of Norton protections changed nothing for email download
Thunderbird only asks for a password when the providers server requests one and it is not saved in its password manager. Maybe we need to look at your server settings to see if you are not contacting the server. Go to the Help Menu and select Troubleshooting Information. Click Copy to Clipboard. Come back here and paste that in a reply window.
tomnik said
Thanks, but no password manager, and temp turn-off of Norton protections changed nothing for email download
Interesting how frequently folk using Nortons products appear in this forum with complaints exactly as yours. I really think there has to be more to it than market share. Personally I blame this Norton feature. https://my.norton.com/extspa/idsafe
Thanks to Airmail and Matt. Here is trouble-shooting stuff, and I shall now go and look at Matt's URL
Application Basics
Name: Thunderbird Version: 52.9.1 User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 Profile Folder: Open Folder
(Local drive) Application Build ID: 20180709124824 Enabled Plugins: about:plugins Build Configuration: about:buildconfig Memory Use: about:memory Profiles: about:profiles
Mail and News Accounts account1: INCOMING: account1, , (none) Local Folders, plain, passwordCleartext
account2: INCOMING: account2, , (pop3) mail.btinternet.com:995, SSL, passwordCleartext OUTGOING: , mail.btinternet.com:465, SSL, none, true
Crash Reports
Extensions Lightning, 5.4.9.1, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
Important Modified Preferences
Name: Value
accessibility.lastLoadDate: 1529634690 accessibility.typeaheadfind.flashBar: 0 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 browser.startup.homepage_override.mstone: rv:1.7.12 dom.apps.reset-permissions: true extensions.lastAppVersion: 52.9.1 font.internaluseonly.changed: true font.minimum-size.x-western: 16 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.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: 18 gfx.blacklist.suggested-driver-version: 6.14.10.4926 mail.openMessageBehavior.version: 1 mail.winsearch.firstRunDone: true mailnews.database.global.datastore.id: 00b7d72d-eee9-4ad1-89be-a33fc3464da mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"7"},"flaggedCol":{"visible":true,"ordinal":"21"},"attachmentCol":{"visible":fals… mailnews.database.global.views.global.columns: {"threadCol":{"visible":true,"ordinal":"7"},"flaggedCol":{"visible":true,"ordinal":"21"},"attachmentCol":{"visible":fals… media.gmp.storage.version.observed: 1 network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1531307685 places.history.expiration.transient_current_max_pages: 122334 plugin.importedState: true print.print_printer: EPSON Stylus Photo RX600 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: 0 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: 1.00 print.printer_Canon_MX920_series_Printer.print_shrink_to_fit: true 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 print.printer_EPSON_Stylus_Photo_RX600.print_bgcolor: false print.printer_EPSON_Stylus_Photo_RX600.print_bgimages: false print.printer_EPSON_Stylus_Photo_RX600.print_command: print.printer_EPSON_Stylus_Photo_RX600.print_downloadfonts: false print.printer_EPSON_Stylus_Photo_RX600.print_edge_bottom: 0 print.printer_EPSON_Stylus_Photo_RX600.print_edge_left: 0 print.printer_EPSON_Stylus_Photo_RX600.print_edge_right: 0 print.printer_EPSON_Stylus_Photo_RX600.print_edge_top: 0 print.printer_EPSON_Stylus_Photo_RX600.print_evenpages: true print.printer_EPSON_Stylus_Photo_RX600.print_footercenter: print.printer_EPSON_Stylus_Photo_RX600.print_footerleft: &PT print.printer_EPSON_Stylus_Photo_RX600.print_footerright: &D print.printer_EPSON_Stylus_Photo_RX600.print_headercenter: print.printer_EPSON_Stylus_Photo_RX600.print_headerleft: &T print.printer_EPSON_Stylus_Photo_RX600.print_headerright: &U print.printer_EPSON_Stylus_Photo_RX600.print_in_color: true print.printer_EPSON_Stylus_Photo_RX600.print_margin_bottom: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_margin_left: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_margin_right: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_margin_top: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_oddpages: true print.printer_EPSON_Stylus_Photo_RX600.print_orientation: 0 print.printer_EPSON_Stylus_Photo_RX600.print_pagedelay: 500 print.printer_EPSON_Stylus_Photo_RX600.print_paper_data: 9 print.printer_EPSON_Stylus_Photo_RX600.print_paper_height: 11.00 print.printer_EPSON_Stylus_Photo_RX600.print_paper_size: 0 print.printer_EPSON_Stylus_Photo_RX600.print_paper_size_type: 0 print.printer_EPSON_Stylus_Photo_RX600.print_paper_size_unit: 1 print.printer_EPSON_Stylus_Photo_RX600.print_paper_width: 8.50 print.printer_EPSON_Stylus_Photo_RX600.print_printer: EPSON Stylus Photo RX600 print.printer_EPSON_Stylus_Photo_RX600.print_reversed: false print.printer_EPSON_Stylus_Photo_RX600.print_scaling: 1.00 print.printer_EPSON_Stylus_Photo_RX600.print_shrink_to_fit: true print.printer_EPSON_Stylus_Photo_RX600.print_to_file: false print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_bottom: 0 print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_left: 0 print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_right: 0 print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_top: 0 print.printer_EPSON_SX125_Series.print_bgcolor: false print.printer_EPSON_SX125_Series.print_bgimages: false
etc. (over max length) Looks as if I should somehow get rid of incoming Account 1
print.printer_EPSON_SX125_Series.print_colorspace:
Since you have the Authentication Method for your SMTP server set to None it is not going to ask for a password. Set that to Normal Password like the POP server is.
Matt, Norton denies that I have a vault, whatever that is, for its Identity Safe, and I don't remember appointing any password management software.
Curiously I have under 'mail' in profile Local Folders Local Folders - 1 pop.ntlworld,com smart mailboxes smart mailboxes - 1
All weird, esp. with ntlworld dead years ago -BUT that is the one with 9 Gb of content.
Airmail, thanks - but done and verified smtp authentication change to normal password; no good, even after re-boot. Still no access to mail through Tbird.
When you first created your profile it would have been ntworld. If you only ever changed the server names on each merger, then there is nothing to cause the folder the mail is stored in to change. Nor is there any reason to change it.
The folder name used to store mail can be changed, but I strongly recommend against it. Change usually results in at least some loss of stored mail unless you really know what you are doing.
Perhaps the best way to determine if this is Thunderbird or an outside package is to boot windows in safe mode with networking. Micrisift offer instructions here. https://support.microsoft.com/en-au/help/12376/windows-10-start-your-pc-in-safe-mode
IF Thunderbird works as it should in that mode, it is third party software running on your machine that is the root cause. If it does not then we need to did a lot deeper into Thunderbird.
Thanks, Matt, but I have been failing for some time to get to the F5 version of Safe Mode; that button just gives me the unhelpful version without networking.
Chosen Solution
tomnik said
Thanks, Matt, but I have been failing for some time to get to the F5 version of Safe Mode; that button just gives me the unhelpful version without networking.
Do you have a wired connection? wifi drivers usually will not load in safe mode.
Stupid of me - didn't think of that. BUT i got rid of two of the five items under mail in my profile, and whether for that reason or another Thunderbird suddenly asked for my password. Problem SOLVED and many thanks to all for help
Sorry to re-open this, Matt, and thanks for help. I was OK for a bit, but power cuts have sent me back to the beginning (BT mail works, Tbird does not) I did connect directly rather than my usual wirelessly, and F5 allowed internet, BUT when I ask Tbird to get mail it still just hangs rather than asking for my (deleted) password as expected. Pity Tbird doesn't use IMAP, which apparently always synchs
Thunderbird uses IMAP or POP depending on what you choose when you set up the account.
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
- Use the button Copy to clipboard to select all. Do not check box "Include account names"!
- Paste this in your post.
What version is your Norton product See https://support.norton.com/sp/en/au/home/current/solutions/v1251038_ns_retail_en_us
Norton is 22.14.2.13
Thanks again, Matt. Clipboard content follows
Application Basics
Name: Thunderbird Version: 52.9.1 User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 Profile Folder: Open Folder
(Local drive) Application Build ID: 20180709124824 Enabled Plugins: about:plugins Build Configuration: about:buildconfig Memory Use: about:memory Profiles: about:profiles
Mail and News Accounts account1: INCOMING: account1, , (none) Local Folders, plain, passwordCleartext
account2: INCOMING: account2, , (pop3) mail.btinternet.com:995, SSL, passwordCleartext OUTGOING: , mail.btinternet.com:465, SSL, none, true
Crash Reports
Extensions Lightning, 5.4.9.1, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
Important Modified Preferences
Name: Value
accessibility.lastLoadDate: 1529634690 accessibility.typeaheadfind.flashBar: 0 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 browser.startup.homepage_override.mstone: rv:1.7.12 dom.apps.reset-permissions: true extensions.lastAppVersion: 52.9.1 font.internaluseonly.changed: true font.minimum-size.x-western: 16 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.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: 18 gfx.blacklist.suggested-driver-version: 6.14.10.4926 mail.openMessageBehavior.version: 1 mail.winsearch.firstRunDone: true mailnews.database.global.datastore.id: 00b7d72d-eee9-4ad1-89be-a33fc3464da mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"7"},"flaggedCol":{"visible":true,"ordinal":"21"},"attachmentCol":{"visible":fals… mailnews.database.global.views.global.columns: {"threadCol":{"visible":true,"ordinal":"7"},"flaggedCol":{"visible":true,"ordinal":"21"},"attachmentCol":{"visible":fals… media.gmp.storage.version.observed: 1 network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1531916516 places.history.expiration.transient_current_max_pages: 122334 plugin.importedState: true print.print_printer: EPSON Stylus Photo RX600 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: 0 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: 1.00 print.printer_Canon_MX920_series_Printer.print_shrink_to_fit: true 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 print.printer_EPSON_Stylus_Photo_RX600.print_bgcolor: false print.printer_EPSON_Stylus_Photo_RX600.print_bgimages: false print.printer_EPSON_Stylus_Photo_RX600.print_command: print.printer_EPSON_Stylus_Photo_RX600.print_downloadfonts: false print.printer_EPSON_Stylus_Photo_RX600.print_edge_bottom: 0 print.printer_EPSON_Stylus_Photo_RX600.print_edge_left: 0 print.printer_EPSON_Stylus_Photo_RX600.print_edge_right: 0 print.printer_EPSON_Stylus_Photo_RX600.print_edge_top: 0 print.printer_EPSON_Stylus_Photo_RX600.print_evenpages: true print.printer_EPSON_Stylus_Photo_RX600.print_footercenter: print.printer_EPSON_Stylus_Photo_RX600.print_footerleft: &PT print.printer_EPSON_Stylus_Photo_RX600.print_footerright: &D print.printer_EPSON_Stylus_Photo_RX600.print_headercenter: print.printer_EPSON_Stylus_Photo_RX600.print_headerleft: &T print.printer_EPSON_Stylus_Photo_RX600.print_headerright: &U print.printer_EPSON_Stylus_Photo_RX600.print_in_color: true print.printer_EPSON_Stylus_Photo_RX600.print_margin_bottom: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_margin_left: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_margin_right: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_margin_top: 0.5 print.printer_EPSON_Stylus_Photo_RX600.print_oddpages: true print.printer_EPSON_Stylus_Photo_RX600.print_orientation: 0 print.printer_EPSON_Stylus_Photo_RX600.print_pagedelay: 500 print.printer_EPSON_Stylus_Photo_RX600.print_paper_data: 9 print.printer_EPSON_Stylus_Photo_RX600.print_paper_height: 11.00 print.printer_EPSON_Stylus_Photo_RX600.print_paper_size: 0 print.printer_EPSON_Stylus_Photo_RX600.print_paper_size_type: 0 print.printer_EPSON_Stylus_Photo_RX600.print_paper_size_unit: 1 print.printer_EPSON_Stylus_Photo_RX600.print_paper_width: 8.50 print.printer_EPSON_Stylus_Photo_RX600.print_printer: EPSON Stylus Photo RX600 print.printer_EPSON_Stylus_Photo_RX600.print_reversed: false print.printer_EPSON_Stylus_Photo_RX600.print_scaling: 1.00 print.printer_EPSON_Stylus_Photo_RX600.print_shrink_to_fit: true print.printer_EPSON_Stylus_Photo_RX600.print_to_file: false print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_bottom: 0 print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_left: 0 print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_right: 0 print.printer_EPSON_Stylus_Photo_RX600.print_unwriteable_margin_top: 0 print.printer_EPSON_SX125_Series.print_bgcolor: false print.printer_EPSON_SX125_Series.print_bgimages: false print.printer_EPSON_SX125_Series.print_colorspace: print.printer_EPSON_SX125_Series.print_command: print.printer_EPSON_SX125_Series.print_downloadfonts: false print.printer_EPSON_SX125_Series.print_duplex: 0 print.printer_EPSON_SX125_Series.print_edge_bottom: 0 print.printer_EPSON_SX125_Series.print_edge_left: 0 print.printer_EPSON_SX125_Series.print_edge_right: 0 print.printer_EPSON_SX125_Series.print_edge_top: 0 print.printer_EPSON_SX125_Series.print_evenpages: true print.printer_EPSON_SX125_Series.print_footercenter: print.printer_EPSON_SX125_Series.print_footerleft: &PT print.printer_EPSON_SX125_Series.print_footerright: &D
tomnik said
Sorry to re-open this, Matt, and thanks for help. I was OK for a bit, but power cuts have sent me back to the beginning (BT mail works, Tbird does not) I did connect directly rather than my usual wirelessly, and F5 allowed internet, BUT when I ask Tbird to get mail it still just hangs rather than asking for my (deleted) password as expected. Pity Tbird doesn't use IMAP, which apparently always synchs
If you want to set up your account as IMAP, instructions are here.
incoming IMAP server: mail.btinternet.com on port 993, SSL/TLS security, authentication = normal password, User name = email address. Outgoing SMTP server: mail.btinternet.com on port 465, SSL/TLS security, authentication = normal password, User name = email address.
If you switch from your current POP account, first copy the existing Inbox and Sent messages to Local Folders, add the account as an IMAP account, and then remove the POP account once the IMAP one is working.
http://kb.mozillazine.org/Convert_a_POP_account_to_a_IMAP_account