థండర్బర్డ్ Community Forum

I have a calendar in thunderbird that synchronizes with my Synology calendar. How can I open the url, user name and password or delete the existing link to my calendar and make a new one which references my synology url etc.

I'd like to receive Thunderbird's calendar alerts once and only once; if I'm not at my computer I don't want to keep hearing them over and over every 10 (?) minutes until manually dismissed. I haven't been able to find any setting (including in about:config) that turns on/off the repeat or sets the timeout between repeat alerts. Is it hardcoded? Or is there somewhere it can be changed? Thanks!

I'm running Thunderbird 140.5.0esr (32-bit) on Windows 10 Pro Build 19045. After the last few updates the columns in the email listings are changing widths from what I've set them, this seems to happen after I close then reopen Thunderbird; which I'm having to do more often these days to resolve weird calendar malfunctions. For instance, the data column would appear so narrow that only the month/day show with "..." at the end, when I know I've looked at this yesterday with the full view of the date and time showing. I've reviewed my options and I've set them individually, set them globally and it makes no difference. Of course I've rebooted, etc. I have over a hundred local folders and they all change differently, of course some look the same but others don't. Most have the same column headings selected but it doesn't seem to matter. Some have the "Correspondents" column selected but many don't.

This is very irritating and I'd like to know why Thunderbird is doing this, and more importantly, how can I prevent this behavior in the future. Thanks,

When I attempt to access the Add-Ons service through Thunderbird, it brings me to an HTML page (https://addons.thunderbird.net/en-US/thunderbird/search/?q=lastpass&appver=147.0.1&platform=Linux) reading

> addons.thunderbird.net > Performing security verification > > This website uses a security service to protect against malicious bots. This page is displayed while the > website verifies you are not a bot.

with the following footer: > Ray ID: 9d07fae58cabaefb > Performance and Security by Cloudflare

It will attempt to connect to Cloudflare to verify a Captcha, but the Captcha itself never renders, and after a period adds the following to the text:

> Why is this verification taking longer? >This verification can take longer due to an older computer or a slow internet connection. > What to do next: > # Wait briefly. Refreshing the page will restart the security verification and may take longer. > # If the verification still does not complete, refresh this page. > # If you are still stuck on this page after a page refresh, refer to Cloudflare’s troubleshooting documentation for more help.

After another period it then cycles the verification page. This continues as long as the tab remains open.

Opening the link listed above in Firefox opens the Addons page as expected.

Similar Captcha pages open on launch, as well as when accessing support or attempting to create a Matrix chat account.

There is a potentially related issue in that images and some icons are not rendered. I will make a separate post asking for help with that if it is not related, but it seemed relevant to mention.

The problem has existed for a long time, and I have checked existing responses without finding a solution, but I didn't get around to asking about it until now.

I am using Thunderbird v. 147.0.1 (64-bit) for Linux with no extensions installed), connected via AT&T broadband service with no proxy set, running under Manjaro 26.0, kernel 6.18.8-1, with the XFCE desktop environment (that last is only mentioned for the sake of completeness). I am using GUFW for my firewall, but the problem persists when the firewall is disabled (something I do not wish to do regularly in any case).

bob.fannon

Feb 14, 2026, 13:01 CST

I have used Thunderbird for a number of years with Plusnet (using POP settings) in the UK. However, Plusnet has transferred their support to a company called Greenby who have made a hash of it and offer very poor support. So, I want to use Outlook as the mail server but I am unable to send any messages via Thunderbird to the Outlook server. I can however download messages with no problems. The error message I get is :- Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) smtp.office365.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'

My default Outgoing Sever settings are :- Server Name : smtp.office365.com Port: 587 User Name: bob.fannon@outlook.com Authentication method: OAuth2 Connection Security: STARTTLS

I have tried deleting the Thunderbird account and re-creating it but still got the same result. I also tried to use my old Icloud account ( having first setup my App Specific password) but got the same result.

My TB 147.0.2 Release channel is using excessive amounts of memory. Below is the memory usage data.

Previously I was on the ESR channel for many years. Also I originally used the Lightning calendar plug.

What I'm seeing is that when TB starts the memory usage is high. If I check at another time on the same day it is sometimes only around 250-350MB.

I've tried suggest options like reducing data in Local Folders (on a separate data drive) but to no avail. As I type now TB memory usage is now only 286.4MB. However rest assured in a while this will jump back to over 3GB and it has an is now 3,151.4MB.

I don't see this on another 2 PCs. One is setup with Locals Folders and the other is just the mail Inbox and sub folders. The only other difference is that the PC with this TB installation also has one Newsgroup server configured.

There surely has to be a bug somewhere causing these excessive memory usages.

Main Process (pid 13380) Explicit Allocations

3,313,474,259 B (100.0%) -- explicit ├──3,179,427,220 B (95.95%) ── heap-unclassified ├─────38,393,176 B (01.16%) ++ window-objects ├─────38,283,520 B (01.16%) ++ js-non-window ├─────23,911,654 B (00.72%) ++ startup-cache ├─────11,605,760 B (00.35%) ++ storage ├──────5,005,920 B (00.15%) ++ images ├──────4,031,040 B (00.12%) ++ threads ├──────2,866,272 B (00.09%) ++ layout ├──────2,273,616 B (00.07%) ++ script-preloader ├──────1,422,800 B (00.04%) ── icu ├──────1,083,184 B (00.03%) ++ xpconnect ├────────917,568 B (00.03%) ++ dom ├────────704,416 B (00.02%) ++ atoms ├────────627,133 B (00.02%) ++ preferences ├────────546,544 B (00.02%) ++ gfx ├────────360,720 B (00.01%) ++ cycle-collector ├────────328,720 B (00.01%) ++ telemetry ├────────318,528 B (00.01%) ++ phc ├────────312,608 B (00.01%) ++ fog ├────────305,312 B (00.01%) ++ url-preloader ├────────212,528 B (00.01%) ++ network ├────────212,480 B (00.01%) ++ string-bundles ├────────166,128 B (00.01%) ++ data-storage ├─────────80,048 B (00.00%) ── profiler/profiler-state ├─────────42,356 B (00.00%) ── skia-font-cache ├─────────19,024 B (00.00%) ++ xpcom ├─────────10,064 B (00.00%) ── memory-reporter-manager ├──────────3,312 B (00.00%) ── xul-prototype-cache/other ├──────────1,904 B (00.00%) ── cookie-service ├────────────624 B (00.00%) ── history-links-hashtable ├─────────────80 B (00.00%) ── cert-storage/storage ├──────────────0 B (00.00%) ── maildb/database(UNKNOWN-FOLDER) ├──────────────0 B (00.00%) ── media/libogg ├──────────────0 B (00.00%) ── spell-check └──────────────0 B (00.00%) ++ webgl

Other Measurements

140,737,488,289,792 B (100.0%) -- address-space ├──138,527,509,839,872 B (98.43%) ── free(segments=402) ├────2,206,026,694,656 B (01.57%) ++ reserved └────────3,951,755,264 B (00.00%) ++ commit

273,510,400 B (100.0%) -- decommitted ├──269,578,240 B (98.56%) -- heap │ ├──268,451,840 B (98.15%) ── decommitted │ └────1,126,400 B (00.41%) ++ unused-pages └────3,932,160 B (01.44%) ── js-non-window/gc-heap/decommitted-pages

5,245 (100.0%) -- event-counts └──5,245 (100.0%) ++ window-objects

1 (100.0%) -- extensions └──1 (100.0%) ── Extension(id=default-theme@mozilla.org, name="System theme — auto", baseURL=moz-extension://d69e3532-324c-43f3-959c-7bc3f6aad1c5/)

3,580,661,760 B (100.0%) -- heap ├──3,311,083,520 B (92.47%) -- committed │ ├──3,272,606,352 B (91.40%) ── allocated │ ├─────28,273,376 B (00.79%) ── bookkeeping │ ├──────8,202,000 B (00.23%) ++ bin-unused │ ├──────1,785,856 B (00.05%) ── unused-pages/dirty │ └────────215,936 B (00.01%) ── waste └────269,578,240 B (07.53%) ++ decommitted

4,942,128 B (100.0%) -- images └──4,942,128 B (100.0%) -- content

  ├──4,934,128 B (99.84%) ++ vector
  └──────8,000 B (00.16%) ++ raster/used

19 (100.0%) -- ipc-channels ├───3 (15.79%) ── PBackgroundParent ├───3 (15.79%) ── PProfilerParent ├───1 (05.26%) ── PAPZInputBridgeChild ├───1 (05.26%) ── PBackgroundStarterParent ├───1 (05.26%) ── PCanvasManagerChild ├───1 (05.26%) ── PCompositorManagerChild ├───1 (05.26%) ── PContentParent ├───1 (05.26%) ── PGPUChild ├───1 (05.26%) ── PImageBridgeChild ├───1 (05.26%) ── PProcessHangMonitorParent ├───1 (05.26%) ── PRDDChild ├───1 (05.26%) ── PRemoteWorkerDebuggerManagerParent ├───1 (05.26%) ── PRemoteWorkerServiceParent ├───1 (05.26%) ── PVRManagerChild └───1 (05.26%) ── PVsyncBridgeChild

20 (100.0%) -- ipc-channels-peak ├───3 (15.00%) ── PBackgroundParent ├───3 (15.00%) ── PProfilerParent ├───2 (10.00%) ── PAPZInputBridgeChild ├───1 (05.00%) ── PBackgroundStarterParent ├───1 (05.00%) ── PCanvasManagerChild ├───1 (05.00%) ── PCompositorManagerChild ├───1 (05.00%) ── PContentParent ├───1 (05.00%) ── PGPUChild ├───1 (05.00%) ── PImageBridgeChild ├───1 (05.00%) ── PProcessHangMonitorParent ├───1 (05.00%) ── PRDDChild ├───1 (05.00%) ── PRemoteWorkerDebuggerManagerParent ├───1 (05.00%) ── PRemoteWorkerServiceParent ├───1 (05.00%) ── PVRManagerChild └───1 (05.00%) ── PVsyncBridgeChild

8 (100.0%) -- js-helper-threads ├──8 (100.0%) ── idle └──0 (00.00%) ── active

47,463,752 B (100.0%) -- js-main-runtime ├──17,759,904 B (37.42%) ++ realms ├──16,789,232 B (35.37%) ++ zones ├──11,440,056 B (24.10%) ── runtime └───1,474,560 B (03.11%) ++ gc-heap

11,691,152 B (100.0%) -- js-main-runtime-gc-buffers ├──11,270,624 B (96.40%) ── used ├─────218,656 B (01.87%) ── free └─────201,872 B (01.73%) ── admin

24,379,392 B (100.0%) -- js-main-runtime-gc-heap-committed ├──20,174,072 B (82.75%) ++ used └───4,205,320 B (17.25%) ++ unused

20 (100.0%) -- js-main-runtime-realms ├──13 (65.00%) ++ system └───7 (35.00%) ++ user

21 (100.0%) -- message-manager └──21 (100.0%) -- referent

  ├──10 (47.62%) -- child-process-manager
  │  ├──10 (47.62%) ── strong
  │  └───0 (00.00%) -- weak
  │      ├──0 (00.00%) ── alive
  │      └──0 (00.00%) ── dead
  ├───6 (28.57%) -- parent-process-manager
  │   ├──6 (28.57%) ── strong
  │   └──0 (00.00%) -- weak
  │      ├──0 (00.00%) ── alive
  │      └──0 (00.00%) ── dead
  └───5 (23.81%) -- global-manager
      ├──5 (23.81%) ── strong
      └──0 (00.00%) -- weak
         ├──0 (00.00%) ── alive
         └──0 (00.00%) ── dead

1,924 (100.0%) -- observer-service └──1,924 (100.0%) ++ referent

868 (100.0%) -- observer-service-suspect ├──437 (50.35%) ── referent(topic=xpcom-shutdown) ├──225 (25.92%) ── referent(topic=memory-pressure) └──206 (23.73%) ── referent(topic=last-pb-context-exited)

363 (100.0%) -- preference-service └──363 (100.0%) ++ referent

0 (100.0%) -- queued-ipc-messages └──0 (100.0%) ── content-parent(Browser, pid=2140, open channel, 0x228780fb828, refcnt=35)

147,366 B (100.0%) -- shared-string-bundles ├───65,420 B (44.39%) ── SharedStringBundle(url="chrome://global/locale/dom/dom.properties", shared=true, refCount=2, sharedMemorySize=65420) ├───24,560 B (16.67%) ── SharedStringBundle(url="chrome://global/locale/layout/htmlparser.properties", shared=true, refCount=2, sharedMemorySize=24560) ├───22,528 B (15.29%) ── SharedStringBundle(url="chrome://global/locale/security/security.properties", shared=true, refCount=2, sharedMemorySize=22528) ├───11,830 B (08.03%) ── SharedStringBundle(url="chrome://necko/locale/necko.properties", shared=true, refCount=2, sharedMemorySize=11830) ├────7,420 B (05.04%) ── SharedStringBundle(url="chrome://global/locale/css.properties", shared=true, refCount=2, sharedMemorySize=7420) ├────6,190 B (04.20%) ── SharedStringBundle(url="chrome://global/locale/layout_errors.properties", shared=true, refCount=2, sharedMemorySize=6190) ├────2,756 B (01.87%) ── SharedStringBundle(url="chrome://global/locale/commonDialogs.properties", shared=true, refCount=2, sharedMemorySize=2756) ├────2,358 B (01.60%) ── SharedStringBundle(url="chrome://global/locale/printing.properties", shared=true, refCount=2, sharedMemorySize=2358) ├────2,174 B (01.48%) ── SharedStringBundle(url="chrome://global/locale/layout/HtmlForm.properties", shared=true, refCount=2, sharedMemorySize=2174) ├────1,488 B (01.01%) ── SharedStringBundle(url="chrome://global/locale/mathml/mathml.properties", shared=true, refCount=2, sharedMemorySize=1488) ├──────246 B (00.17%) ── SharedStringBundle(url="chrome://branding/locale/brand.properties", shared=true, refCount=2, sharedMemorySize=246) ├──────226 B (00.15%) ── SharedStringBundle(url="chrome://global/locale/xul.properties", shared=true, refCount=2, sharedMemorySize=226) └──────170 B (00.12%) ── SharedStringBundle(url="chrome://global/locale/svg/svg.properties", shared=true, refCount=2, sharedMemorySize=170)

28,598,376 B (100.0%) -- window-objects ├──16,114,528 B (56.35%) ++ dom ├──12,432,968 B (43.47%) ++ layout └──────50,880 B (00.18%) ── property-tables

          262,144 B ── font-list-shmem
                0 B ── gfx-textures
                0 B ── gfx-textures-peak
                0 B ── gfx-tiles-waste
                  0 ── ghost-windows
                0 B ── gpu-committed
                0 B ── gpu-dedicated
                0 B ── gpu-shared
    3,272,606,352 B ── heap-allocated
        1,048,576 B ── heap-chunksize
                  0 ── imagelib-surface-cache-already-present-count
          304,880 B ── imagelib-surface-cache-estimated-locked
          314,928 B ── imagelib-surface-cache-estimated-total
                 85 ── imagelib-surface-cache-image-count
                 52 ── imagelib-surface-cache-image-surface-count
                 85 ── imagelib-surface-cache-locked-image-count
                 45 ── imagelib-surface-cache-locked-surfaces-count
                  0 ── imagelib-surface-cache-overflow-count
                  0 ── imagelib-surface-cache-table-failure-count
                  7 ── imagelib-surface-cache-tracked-cost-count
                  7 ── imagelib-surface-cache-tracked-expiry-count
                  0 ── imagelib-surface-cache-tracking-failure-count
          454,656 B ── js-main-runtime-temporary-peak
                  8 ── js-main-runtime-zone-count
    3,386,552,320 B ── private
    3,497,312,256 B ── resident
    3,369,873,408 B ── resident-unique
       29,638,345 B ── shmem-allocated
        2,612,339 B ── shmem-mapped
        6,256,466 B ── system-heap-allocated
2,209,978,449,920 B ── vsize

70,172,792,717,312 B ── vsize-max-contiguous

                0 B ── wasm-runtime
                  0 ── webgl-buffer-count
                0 B ── webgl-buffer-memory
                  0 ── webgl-context-count
                  0 ── webgl-renderbuffer-count
                0 B ── webgl-renderbuffer-memory
                  0 ── webgl-shader-count
                  0 ── webgl-texture-count
                0 B ── webgl-texture-memory

End of Main Process (pid 13380)

I currently have two email accounts in Thunderbird (both from Virgin), and want to add a further one (from Hotmail). The new account is up and working, but I've only been partially successful in adding it to Thunderbird. I followed the procedure given in the Support Article "Automatic Account Configuration" and this worked up to a point, but it failed at Step 4 (or possibly 5). Thunderbird seems to be able to recognise the new account and add it to the on-screen list, but It claims that it can't find any messages, although I know that there are at least 10 in its Inbox on Outlook. Furthermore, although my other two accouts have subfolders such as "Inbox, Drafts, Spam, Sent, etc." the only subfolder that appears in the new account is "Inbox", which remains stubbornly empty!

I'm attaching two screenshots. The first one shows my Firefox screen with the three accounts and their subfolders (collapsed for "richardandmaya@ntlworld.com") in the left hand column. The new one is the one named "ailuros2@hotmail.com". The second screenshot shows the new account seen via its native Outlook, which shows all the messages that I know are there but which Thunderbird can't see.

Strangly, I seem to be able to send messages from the new account to other accounts.

Any suggestions?

Upon starting Thunderbird today, it appears the connection to my two Outlook exchange accounts (through an Owl extension) are no longer functional. I can receive messages but I cannot send them. I have attached images of the error it returns first (Error1) and then the screen that results upon refresh (Error2). I can reach and send mail from my accounts using Outlook365 web access, so it must be a Thunderbird configuration problem. Please help!

Since loading a fresh copy of Thunderbird on a new bigger disk on my Ubuntu laptop, whenever I start it up it opens up all my email folders and sub-folders. I have lots, and it takes time to collapse them all manually. I monitor two other email accounts for a club which also have quite a few folders and sub-folders - same happens on all of them. This did happen occasionally with my old version, but happens every time now with 140.7.1esr (64-bit) running under ubuntu-snap-build - 1.0.

Hi all,

I use SpamAssassin but even "When Thunderbird determines that they are unwanted" has been ticked" no one of my spams are not marked as read ?!?!

This is annoying, is it a bug or something I missed?

What can I do ?

Thanks in advance for your help.

Best regards.

Philippe

My "old" laptop (Windows 10) failed & refused to turn on ever again and it's been replaced by a new laptop (Windows 11). Long existing Email served by Mozilla Thunderbird has been loaded into new laptop but all that was loaded was about 6 current unread Emails in the Inbox and NOTHING in either Address Books (should be 30 or so in each) and NO FOLDERS (should be about 15 - 20). I own & run a business so all of this data/info is crucial but because the data currently lies within a laptop that died it appears it can't be retrieved by "normal" procedures. I need help here - lots of it.

Cheers and thank you. Pam E Victoria Australia

After providing my existing twc.com email address and other requested information, Thunderbird did a search and came up with "The following settings were found by probing the given server." I used those settings and attempted to create a Tbird-based account. I got this error message: "Thunderbird failed to find the settings for your email account." Which seems odd since Tbird provided those settings by searching the server. What can I do now? I hate to go back to MS Office but I need email and I've spent two days trying to figure this out, including a couple of hours on the phone with Spectrum (they were just as baffled as I am). I still can't use Tbird for email but pls email me at [edited from community support forum] @twc.com and I can access it on my old MS Office computer.

Scary behavior of 'Local Folders': I'm moving an IMAP account from one server to an other. I copy all emails from old server IMAP account to a place described as "Local Folders". I then delete the account connected to the old server. WTF: the the local folders to which I copied the messages are now GONE. My plan was to recreate the account to the new server, then copy messages from LocalFolders to IMAP. But the LocalFolders got deleted along with the IMAP account. This I was doing in a separate profile from my own, as it's for a friend I'm helping with a hosting move.

In my own profile: For more than a decade, I have been maintaining the size of my mailboxes, by moving older messages to LocalFolders. As it happens, for these, I did indeed direct the folder to a separate drive, which also gets backed up offsite. My concern is that 'Local Folders' are portrayed as being INDEPENDENT of IMAP accounts. This is VERY POOR design, to allow a user to delete data they thought was safely stored locally while they recreate a moved or misbehaving account. I have dozens of Local Folders. Five years ago, I abandoned an entire domain name and it's email accounts. I know I still have those emails in my local folders despite having deleted the IMAP accounts from my profile. I fear that the current version, by default, might not be so respectful of my data. Can someone please explain? Where are the links that TIE an IMAP account to Local Folders, and how do I sever that link?

In my case, the source account still exists. I can repeat my steps, but for some other unfortunate users, this may not be the case.

Yesterday, out of the blue, one of my Spectrum email accounts asked me to sign in. I tried entering my existing credentials several times, but failed to sign in. I tried to recreate the account, but, it fails each time with "Thunderbird failed to find the settings for your email account". I tried using the account hub and it fails with the same message, with a sub message of "can't find a server".

I've been on the phone with Spectrum 5 times in the past 24 hours. They claim that it's a Thunderbird problem since I can access the email in question if I go through their web interface.

Can anyone help with this?