Release Notes

Thunderbird Desktop

Version 52.9.0 | Released July 3, 2018

Check out the notes below for this version of Thunderbird. As always, you’re encouraged to tell us what you think, or file a bug in Bugzilla.

System Requirements: • Window: Windows XP, Windows Server 2003 or later • Mac: Mac OS X 10.9 or later • Linux: GTK+ 3.4 or higher Details here.

Please refer to Release Notes for version 52.0 to see the list of improvements and fixed issues.

What’s Changed


Thunderbird will now prompt to compact IMAP folders even if the account is online. Note: Under certain circumstances an incorrect estimate of the expected gain is shown.

What’s Fixed


Complete fix of the EFAIL vulnerability: 1) Removing some HTML crafted to carry out an attack. 2) Optionally: Not decrypting subordinate message parts that otherwise might reveal decrypted content to the attacker. Preference mailnews.p7m_subparts_external needs to be set to true for added security.


Various problems when forwarding messages inline when using "simple" HTML view


Various security fixes

Known Issues


Deleting or detaching attachments will corrupt messages under certain circumstances

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