Thunderbird 140.17.0esr — the first minute without a single click
How we tested: a clean Debian 13 in a disposable container; source — package thunderbird 1:140.17.0esr-1~deb13u1 from the Debian repository. Run as a regular user on a virtual screen, 60 seconds, nothing clicked. 16.10.2026. Every network request and every file written was recorded; the code was not decompiled. The container was deleted afterwards.
Package SHA-256: ef46319ef6397741c43d276e3779630c994e67ea6f165cf2145148304389c5df
Summary
| What we checked | Result |
|---|---|
| Built-in telemetry, crash reporting, analytics, ad SDKs | Mozilla Telemetry / Glean (usage statistics) |
| Network requests in the first minute | 8 server names |
| Known trackers among the servers | none |
| Files written in the first minute | 202 |
| The program ran the whole time | yes — process alive at the end |
What is built in
15041 files (349 MB) were checked.
| SDK | Purpose | Found in |
|---|---|---|
| Mozilla Telemetry / Glean | usage statistics | usr/share/thunderbird/omni.ja!/modules/JSONFile.sys.mjs |
Addresses of known trackers in the program’s files — addresses in code, not requests:
| Tracker | Addresses | Mentions |
|---|---|---|
sb-ssl.google.com, safebrowsing.google.com, developers.google.com, code.google.com | 154 | |
| Microsoft Bing Ads | bing.com, www.bing.com | 39 |
| Google APIs | www.googleapis.com, safebrowsing.googleapis.com, storage.googleapis.com | 22 |
| Mail.ru | win.mail.ru, e.mail.ru, o2.mail.ru, go.mail.ru | 20 |
| Яндекс.Метрика | mail.yandex.ru, yandex.ru, www.yandex.ru, suggest.yandex.ru | 10 |
| Yahoo | search.yahoo.com, api.login.yahoo.com | 6 |
| jQuery CDN | jquery.com | 5 |
| Twitter/X | twitter.com, developer.twitter.com | 4 |
| Cloudflare | challenges.cloudflare.com | 4 |
www.reddit.com | 3 | |
| YouTube | www.youtube.com | 3 |
| unpkg | unpkg.com | 2 |
Where it connected
| Server | How | From second | Times | Known tracker |
|---|---|---|---|---|
autoconfig.thunderbird.net | connection | 4.9 | 1 | — |
incoming.thunderbird.net | connection | 6.2 | 1 | — |
live.thunderbird.net | connection | 3.5 | 2 | — |
location.services.mozilla.com | connection | 3.0 | 1 | — |
services.addons.thunderbird.net | connection | 32.3 | 1 | — |
start.thunderbird.net | DNS lookup only | 5.9 | 3 | — |
thunderbird-settings.thunderbird.net | connection | 32.3 | 1 | — |
www.mozilla.org | connection | 13.5 | 2 | — |
A DNS lookup is not yet a connection: the program looked up the server’s address. But the lookup itself is visible to the ISP and the DNS server.
What it wrote to disk
Folders the program wrote files to during the minute:
| Folder | Files |
|---|---|
~/.cache/mesa_shader_cache_db | 102 |
~/.cache/thunderbird | 53 |
~/.thunderbird/y7jougcd.default-default | 40 |
~/.cache/fontconfig | 2 |
~/.cache/dconf | 1 |
~/.thunderbird/1bde33db.default | 1 |
~/.thunderbird/Crash Reports | 1 |
~/.thunderbird/installs.ini | 1 |
~/.thunderbird/profiles.ini | 1 |
How to read this card
- This is the first minute after launch with no action at all: what the program does on its own. Normal use may involve more requests.
- A “built-in SDK” means the library’s code was found. It does not prove data transfer, and an address in the code is not a request.
- The review was made automatically using a single method. You can check any program yourself here.