How to Extract Email Addresses from Thunderbird
Summary: You can extract email addresses from a Thunderbird mailbox in three ways. First, export the Collected Addresses book and any custom address books to CSV from Thunderbird’s Address Book window. Second, run a regex script on the Thunderbird profile’s MBOX folders to pull every From, To, and Cc value into a clean text file. Third, use a dedicated Thunderbird email address extractor that scans every folder and saves a deduplicated CSV. The Address Book route is the easiest. The dedicated tool is the fastest and also captures body-level addresses.
Where Thunderbird Stores Your Email Addresses
Thunderbird keeps addresses in two places. If you are coming from another client, first import eM Client to Thunderbird so all your mail sits in one profile before extraction. First, the Address Book holds Personal and Collected Addresses. Second, message folders store raw addresses inside MBOX files on disk.
However, the Address Book only contains people you wrote to or saved manually. As a result, it misses incoming senders and addresses inside conversation history.
The MBOX files hold every From, To, Cc, and Reply-To value that ever passed through the mailbox. Therefore, a full extraction often needs both sources.
What You Need Before You Start
First, gather the basics. Then pick the method that matches your need.
- Thunderbird installed and pointed at your mailbox.
- Access to the Thunderbird profile folder (under
%APPDATA%\Thunderbird\Profileson Windows). - PowerShell or grep, if you want Method 2.
- A target CSV or TXT file location.
- A backup of the profile folder before any script run.
Method 1: Export the Collected Addresses Book to CSV (Easiest)
Thunderbird builds the Collected Addresses book automatically. Every time you reply to someone new, the address lands in this book.
Open the Thunderbird Address Book
First, open Thunderbird. Then click the Address Book icon in the toolbar or press Ctrl + Shift + B.
Next, click Collected Addresses in the left pane. You should see every contact Thunderbird saved on your behalf.
Export Personal and Collected Addresses to CSV
Next, click Tools > Export and choose Comma Separated (CSV). Then save the file.
Repeat the export for the Personal Address Book and any custom books. Finally, merge the CSV files in Excel and remove duplicates.
Tip: The Collected Addresses book only stores senders you replied to (see our Thunderbird Address Book contacts overview for the full file layout). For a complete sender list, also use Method 2 or Method 3.
Method 2: Run a Regex Script on the MBOX Profile Folder
Thunderbird stores each folder as a single MBOX file. MBOX is plain text, so a regex script can scan every message at once. The same script also works to extract email addresses from any MBOX file outside Thunderbird.
Locate the Thunderbird profile folder
First, press Windows + R and type %APPDATA%\Thunderbird\Profiles. Then open the profile that ends in .default and find the Mail or ImapMail subfolder.
Each account folder holds files named after your folders (Inbox, Sent, Archives). These are your MBOX files.
Run the PowerShell or grep script
Next, open PowerShell in the Mail account folder. Run:
Get-ChildItem -Recurse | Where-Object { -not $_.PSIsContainer } | Select-String -Pattern '[\w\.-]+@[\w\.-]+\.\w+' -AllMatches | ForEach-Object { $_.Matches.Value } | Sort-Object -Unique | Out-File thunderbird-emails.txt
Then open thunderbird-emails.txt. As a result, you get every unique address from every folder in seconds.
Why this works: MBOX is plain text. Therefore, regex captures From, To, Cc, Reply-To, and any address that appears in message bodies.
Method 3: Use a Dedicated Thunderbird Email Address Extractor Tool
Sometimes you want a guided workflow with previews, field filters, and name-to-address pairing. In that case, a dedicated extractor is the fastest path.
When to choose this method
Choose this route when the Thunderbird profile is large, when you need addresses filtered by field (To, Cc, From, Body, Header), or when you want a single CSV with names paired to addresses. Additionally, it helps when you also need to pull addresses from attachments.
Steps
First, download the Thunderbird email address extractor on your Windows PC. Then install and launch the tool.
Next, click the Open tab on the application screen.
Then go to Desktop Email Clients and choose Thunderbird Accounts. The tool auto-detects configured profiles.
Next, pick the account. The tool loads every folder and shows a preview on the left panel. The same tool can also extract attachments from Thunderbird when you need files instead of email addresses. If Thunderbird is not configured, click Choose Folder and point at the profile location.
Then click the Extract tab and pick Email Addresses from the drop-down.
Next, pick the fields you want (To, Cc, From, Subject, Message Body, Message Header). For example, pick only From for a clean sender list.
Finally, browse to the destination folder and click Save. The tool writes a deduplicated CSV or TXT with every unique address.
Note: The tool also pulls addresses from message bodies and attachments. As a result, you capture every address that ever passed through the mailbox.
Which Method Should You Choose?
Use Method 1 (Address Book export) when you only need contacts you have already saved or replied to.
Use Method 2 (regex on MBOX) when you want a free, scriptable option and need addresses from every message header and body. It also fits scheduled tasks.
Use Method 3 (dedicated tool) when you want field filtering, name-to-address pairing, attachment scanning, and a guided UI.
Frequently Asked Questions
Can I extract email addresses from Thunderbird without leaving the app?
Yes. Method 1 uses Thunderbird’s built-in Address Book export. Therefore, no extra software is required.
Will the extracted list include duplicates?
No, if you use PowerShell with Sort-Object -Unique or a dedicated extractor. Both deduplicate automatically.
Can I pull addresses only from sent items or only from received mail?
Yes. Point Method 2 at the Sent or Inbox MBOX file. Alternatively, filter by folder at extraction time in Method 3.
Are Thunderbird files modified during extraction?
No. All three methods are read-only. The original profile stays untouched. However, always back up the profile folder before any script run.
Can I extract names along with email addresses?
Yes. Method 1’s CSV export includes display names. The dedicated tool also pairs names with addresses in the output.
What if I use Thunderbird with IMAP and messages are not cached locally?
Switch the folder to Offline > Synchronize first. Then run Method 2 or Method 3 on the now-local MBOX files.
Related Guides
- Extract Email Addresses from OST File: the same task for Outlook OST mailboxes.
- Extract Email Addresses from vCard Files: for contacts stored in VCF format.
- Extract Phone Numbers from vCard Files: pair this with the email extractor for a full contact export.