Thunderbird Community Forum

I'm using Thunderbird on Ubuntu 24 and have some messages in some mailboxes that have lost their headers. I'm trying to fix them.

Early (1980's command line mail & mailx) mbox files were pure text with messages delimited by a blank line followed by a line starting with 'From ' (or possibly 'From: '). When I open a Thunderbird mbox file in 'vi' it is 'converted', or so it says. I'm wondering what this 'conversion' is and why it's needed.

Please could someone tell me what the strict rule that delimits messages in a Thunderbird mbox file is, and what is it that 'vi' cannot handle that requires 'conversion'?

Thanks

153.3.1esr (64-bit) Thunderbird Meadow Thunderbird Snap for Ubuntuubuntu-snap-build - 1.0

I tried to add my Outlook account to Thunderbird, I entered my details and clicked Continue but it stuck in the "Looking up configuration" screen. I then tried doing manual configuration and entered outlook's IMAP and SMTP server but there's an error message that said "Failed logging in to server" and when I try again it became "Incoming server already exists." An OAuth2 popup appears only after I closed Thunderbird and since Thunderbird is already closed the address it's trying to return to (127.0.0.1:41003) is no longer monitored.

I no longer have a right click menu available for photos in an email. There is only the option to zoom in or back out. My screen does not match what directions Google has to offer to fix the bug.

Hello,

I urgently need technical assistance with a serious issue involving Mozilla Thunderbird and my professional certified email account (Aruba PEC, Italy).

I have been using Thunderbird to manage my professional email correspondence for several years.

I organize processed emails into yearly folders (2024, 2025, 2026, etc.), located under my email account in Thunderbird, not under Local Folders.

Today, October 13, 2026, I discovered that all emails dated January through September 2026 have disappeared from my "2026" folder.

Only emails from October 2026 remain.

The missing messages include professional correspondence, certified email delivery receipts, acceptance receipts, and potentially legally significant communications.

What I have verified so far:

The "2026" folder exists both in Thunderbird and in Aruba Webmail.

Both display the same remaining emails from October.

The Trash folder is empty.

The 2024 and 2025 folders still contain their messages.

Thunderbird's retention settings are configured to "Don't delete any messages."

The "2026" folder inherits the account's retention settings.

I did not knowingly delete or move these messages.

Aruba customer support informed me that they cannot restore the missing emails.

I checked Windows Previous Versions and OneDrive, but no backup was found.

I located the local Thunderbird mailbox file named "2026" in the profile's ImapMail directory. It is approximately 3 MB.

Inspection of a copy of this file did not reveal message headers from before October 2026.

I could not find another larger copy of this mailbox file in the Thunderbird profile.

I occasionally remove unused folders under "Local Folders", but I do not recall deleting any folder containing these messages. The affected "2026" folder is located under the IMAP email account.

My questions are:

Could Thunderbird have deleted or moved these messages automatically despite the retention settings?

Could IMAP synchronization, folder corruption, message filters, or compaction explain this situation?

Are there any additional Thunderbird files, caches, databases, or recovery methods worth investigating?

Is there any way to identify when or how the messages were deleted?

What steps should I take to prevent further data loss?

I have preserved a backup copy of my Thunderbird profile and would prefer not to perform potentially destructive operations.

This is particularly serious because the missing messages are part of my professional and legally relevant correspondence.

Any technical guidance would be greatly appreciated.

Thank you very much for your help.

Tried adding my outlook account, it said that the account settings are found automatically so when I left those options unedited and clicked continue it showed this error. Have no idea what went wrong though.

I like using Threads, to keep repeated exchanges together.

Today, I selected one of my emails, then Edit as New, to edit and send some of the content to a couple others, independent of the thread.

but now, those emails to others are linked to the initial thread with the original recipient. I do not want them to be linked to that conversation thread, but instead for them to be in their own thread if a continuing email exchange occurs with these.

I do not want to remove them from history, but rather to merely break the existing link to the thread involving a totally unrelated recipient.

I'd like to resize an embedded image in an email. The bottom right handle is on the far right side. If I attempt to hover over the handle a scrollbar obscures the handle: it is not possible to grab it and resize the image.

How do I resize large images in Thunderbird emails?