Release notes - Proton Mail Bridge (2025)

New

• Bridge now performs a quick database health check on startup tocatch potential issues early.

Fixed

• Resolved issues regarding labels and folders not always syncingcorrectly.

Changed

• Mailbox handling is more reliable, with better error detection andfewer sync issues.

New

• Added more detailed local logging for label-related operations andvault key information.
• Bridge now remembers the last keychain helper used on Linux.

Changed

• Username and password handling during login is now more robust.

Fixed

• Fixed autostart shortcut creation on Windows for usernames withspecial characters.
• Improved reliability when many mail changes are made from otherclients.

Changed

• Security and compatibility upgrade for the graphical userinterface.

Changed

• Revised update logic to account for supported operatingsystems.

Changed

• Updated Go to version 1.23.4.
• Various dependency updates.
• Improved email update mechanism during initial synchronization.

Fixed

• Cut and paste options no longer appear in read-only textfields.

New

• Added support for IMAP AUTHENTICATE PLAIN.

Changed

• Email headers with multiple values now retain their originalorder.
• Remove all cached data when an account is removed from Bridge.
• Enhanced the user experience for Human Verification Prompts.
• Restored the ‘-h’ (help) flag in the CLI.

Fixed

• Addressed rare issues with creating, updating, and sending draftsduring and after synchronization.

Fixed

• Disable the keychain test on macOS.

New

• Added an option to hide the Bridge tray bar icon on macOS.
• Added new parameters to the CLI help command.

Changed

• Adjusted the macOS profile installation dialogue to reflect the newmacOS version profile installation changes.

Fixed

• Enhanced message importing, draft creation and email sending forrare edge cases.

Changed

• Modified behaviour of updater when an update file cannot bedownloaded or verified.

Fixed

• Fixed an issue that would prevent Bridge from starting if theinitials of an account’s user are empty.
• Fixed import of messages with ‘Multipart/Related’ MIME type.

New

• Added a command line parameter to enable or disable keychain checkon macOS.
• Introduced remote message display to Bridge to be able tocommunicate to users during incidents.
• Added context menu to text fields for easier interaction.

Changed

• Improved knowledge base article recommendation during customersupport ticket creation.

Fixed

• Bridge can properly handle home folder name changes on macOS.

New

• Added a Repair function under the advanced settings that fixes anylocal data or configuration corruption without the need to reconfigurethe email client.

Changed

• Various stability and security improvements.

Fixed

• Fixed an issue that prevented Bridge from starting if the IMAP orSMTP port was already in use.

New

• Added human verification capabilities to Bridge, so users canunblock anti-abuse blocked clients without contacting customersupport.
• Improved setup and update experience by installing Certificates onmacOS for Outlook for Mac email client.

Fixed

• Improved logging for easier troubleshooting.
• Added tooltip to the Bridge tray icon.

New

• Improved sync troubleshooting by tracking in the application logsthe path of the messages.

Fixed

• Resolved an issue that happens when importing a message that wasinvolved in forwarding.
• Resolved an issue that can happen when sending attachments that hasnon-unicode encoding.

New

• Updated Go version to 1.21.6 and couple of golang libraries.
• Updated keychain access library.
• Improved log format and content.

Fixed

• Prevented various startup and sync issues.
• Resolved apple configuration profile issue.

Fixed

• Resolved an issue that prevented Windows and Linux users to autoupdate to newer versions of Bridge, and in some cases reverted to aprevious version of Bridge. NOTE: All Bridge versions that are betweenv3.2.0 and v3.8.1 (inclusive) need to be updated to the latest Bridgeversion manually. If you have any questions, please get in touch withProton customer support or follow the knowledge base instructions:https://proton.me/support/protonmail-bridge-manual-update .

New

• Added suggestions to relevant KB articles in the in-app bug reportform and notifications.

Fixed

• Improved duplicate detection in sent folder.
• Improved Bridge interaction with keychain.
• Various errors during sending.

New

• Adjusted size of window on low resolution display.
• Improved interaction with system keychain.

Fixed

• Resolved multiple send and draft issues.
• Prevented de-synchronization during migration step.
• Improved login and synchronization user experience.
• Resolved multiple send and draft issues.
• Improved behaviour on unstable network connection.

New

• Setup wizard introduced to improve the onboarding and connecting theemail client.
• Improve the user experience for adding local certificates onmacOS

Fixed

• Update correctly the status of synchronization in application windowfor several edge-cases.
• Prevent message duplicates in Sent folder.

Fixed

• Avoided situation which lead to not receive new mails.

New

• Update crypto libraries (gopenpgp v2.7.3)

Fixed

• Wrong mailbox hierarchy when recovering from undefined syncstate.

New

• Reduced synchronization resource consumption. This change leads tolonger synchronization time.
• Added email send, delete, and status change functionalities duringsynchronization to not depend on synchronization time. Theseinteractions are shared with Proton servers immediately. The changes onProton servers during synchronization are processed in Bridge only afterthe synchronization is finished.
• Synchronization progress bar is updated more frequently.
• The synchronization progress bar represents the wholesynchronization process, not only the progress ahead from the time whenthe synchronization is started/resumed. Restarting the Bridge duringsynchronization will not reset the synchronization progress bar tozero.
• Introduced a new error reporting workflow to improve customersupport response time and quality.
• Improved Bridge reliability by reducing its dependency on fileoperation failures.
• Relaxed Bridge email header parsing rules to allow more emails toimport.

Fixed

• Correctly reset Bridge on Windows.
• Prevent deleting message when moving it from trash in AppleMail.
• Fix async issues in Bridge services.
• Fixed a bug that caused re-synchronization when Proton servers werenot available during synchronization.
• Fixed some cases when sent messages are duplicated in the sentfolder.
• Emails with missing keys (e.g., forgotten password) are now listedin the email client (still encrypted).
• A new Bridge session identifier is properly created when the Bridgeuser interface crashes.
• When a message is added to the trash, Bridge removes all labels tohave the same behavior as other Proton email clients.
• Fixed the stuck signing in after trying to add an already-addedaccount again.

Fixed

• Fixed the occasional “No values changed” error when sending emailswith Apple Mail

New

• Added a debug option to the Bridge command line interface to crosscheck local mailbox state against Proton server state
• Switched to a new database layout to significantly speed upcommunication with email clients, and to prevent errors when Bridgeprocesses many data quickly
• Made small UI changes to be consistent with other Proton products,and to have an easier to understand status view of the Bridge state
• Added numerous changes to make troubleshooting more efficient,including the introduction of a new log file organization
• Simplified setup experience by removing the Account details dialogwhen Bridge is auto-configured with Apple Mail

Fixed

• Fixed the debug option on the Bridge command line interface to notmark emails as read on the server
• Made Bridge to handle better when Proton servers are overloaded
• Added numerous fixes to prevent application crashes, to keep Bridgeconsistent with the Proton servers, and to improve email parsingcorrectness
• Added small fixes that help running automated Bridge tests

New

• Improved Bridge debugging capabilities by adding more information tothe application logs
• Started measuring the Bridge setup experience

Fixed

• Cannot permanently delete new messages
• Temporarily removed clickable notifications on Linux to not raisethe Bridge window when receiving non-Bridge notifications

New

• Reduced the number of occasions when email clients ask for Bridgecredentials
• Added new Bridge notifications to help users to configure andtroubleshoot their email clients
• To avoid the need to reconfigure email clients, Bridge remembers theold account password when an account is re-added (removed and addedagain)
• Further improved logging to support troubleshooting
• 2 factor authentication (2FA) is submitted automatically afterentering a code
• Removed the requirement of having an administrator account on macOSto install Bridge

Fixed

• Fixed numerous crashes
• Fixed the case when an email could not be sent if a PDF was attachedto the email
• Added varioius bugfixes and security improvemenets
• Reduced the Bridge cache size by cleaning up temporary emails thatwere saved during failed initial synchronizations
• Further reduced the chance of desyncronization between the emailclient and Bridge

New

• Enhanced Proton infrastructure protection
• Enhanced the integration with the operating system by replacingstatus windows with native tray icon context menu
• Switched to two columns layout on the account details page to makethe informaion easier to access
• Improved logs to support troubleshooting
• Added optional usage sharing to support user experienceimprovements. Additional information about data sharing can be found onour supportpage.
• Implemented smart picking of default IMAP and SMTP ports
• Added various security and performance improvements

Fixed

• Replaced invalid email addresses with empty field for new drafts soit can be syncronized across Proton clients
• Improved crash handling
• Fixed label / unlabel performance when applied on large amount ofemails
• Fixed “reply to” related issues
• Updated build instructions
• Announced IMAP ID capability to email clients

Fixed

• Added a missing error handler that can make the initialsynchronization to stuck

New

• Significantly reduced memory consumption both during synchronizationand communication with email clients
• Added synchronization indicator to the graphical user interface(GUI)
• Added “Close window” and “Quit Bridge” buttons to the mainwindow
• Added command line switches to control GUI rendering
• Switched to software rendering on Windows to support old graphicscards
• Added support for Proton’s Scheduled send feature
• Avoided making email clients to ask for Bridge credentials when theystarted faster than Bridge at startup
• Added a notification when a user is signed out from Bridge in thebackground
• Improved desynchronization avoidence by setting UIDValidity from thecurrent time
• Started updating emails in the email clients frequently when Bridgeis started after not being online for longer period of time
• Improved error detection and handling
• Optimized Recovered Messages folder size by not adding a message tothe folder if that message has been added to it before(deduplication)

Fixed

• Fixed transparent window with old graphics cards or virtual machineson Windows
• Reduced notifications that does not require user actions
• Improved exception / crash handling
• Improved handling complex MIME types
• Reduced the source of errors that can lead to gRPC related errormessages
• Fixed sub-folder rename issues
• Fixed various bugs related to secure vault handling, networkcommunication errors, Proton server communication, operating systemintegration.

New

• Extended the migration from the previous major Bridge version withcertificates
• Improved error detection

Fixed

• Fixed the misplaced .desktop file on Linux
• Fixed DBUS secret service integration (e.g., KWallet, KeePass)
• Made Bridge more resilient against Proton server outages

New

• Added better explanation when an email cannot be sent because ofnon-existing email addresses
• Added a dialog to Bridge where users can repair the application whenit encounters an internal error
• Improved error detection

Fixed

• Reduced the cases when Bridge could not restart automatically
• Fixed the bug that could cause email states (e.g., read, unread,answered) to come out of sync with the web application. NOTE:This fix is only applied to new emails. In order to fix older emails inBridge, the account in Bridge needs to be removed and addedback.
• Fixed incorrect subject parsing caused by double quotes

New

• Improved inter-process communication error detection
• Improved exceptions related error detection

Fixed

• Fixed numerous sources of errors leading to logout (internalerrors)
• Fixed inter-process communication related startup issues (e.g.,gRPC, service configuration file exchange)

New

• Improved event processing related error handling

Fixed

• Fixed manual update errors on Windows by ensuring that all new filesare deployed by the Bridge installer

New

• Rewrote a significant part of Bridge to improve overall Bridgestability and performance
• Open sourced and integrated a new IMAP library, Gluon(https://github.com/ProtonMail/gluon)
• Open sourced and integrated a new Proton API library, Go Proton API(GPA) (https://github.com/ProtonMail/go-proton-api)
• Significantly improved error detection and unexpected errorhandling
• Improved email sending performance
• Improved synchronization performance
• Added new command line argument for software rendering
• Extended the coverage of the Bridge data that is encrypted on theusers’ computers
• Added an option to the graphical user interface to export TLScertificates
• Reimplemented the user interface (upgraded to the Qt 6 userinterface library)
• Added native Apple Silicon macOS support
• Added an option to change IMAP connection mode
• Added subfolder support
• Added a new icon for the .dmg installer
• Increased automated test coverage

Fixed

• Desynchronization while creating a draft email
• Fixed sub-folder creation issues
• User name and password validation messages are shown only when theSign in button is pressed
• Improved handling SMTP send deduplication
• Improved robustness of Bridge restart
• Fixed the user notification for occupied Bridge ports
• Fixed vulnerabilities of golang.org/x/crypto
• Added the missing Library on Fedora/Gnome for 2.3 to 2.4 update
• Added digital-signature for DLLs (to avoid the Windows Securityalert, and to show if Bridge is coming from a trusted publisher)
• Fixed many Qt 6 related Linux and Windows update process issues
• Changed the default location of the database and storage files toavoid conflicts with cache cleaner applications

New

• Feature to hide All Mail from IMAP client
• Enable automatic configuration on macOS Ventura
• Improved the scope of local logs

Fixed

• Visibility of Dependencies in Bridge GUI
• Potential crashes on parallel LIST command

New

• Updated GUI colours to reflect new Proton’s colours theme
• Renamed ProtonMail Bridge to Proton Mail Bridge - installers,keychain etc.
• New Bridge systray icons for all OSes
• New Bridge application icons for all OSes
• Visual update of macOS and Windows installers
• Add label/folder filtering to pmapi
• Use one buffered event for internet status changes - to eliminatefalse-positive connection errors
• Added a modal to prompt the user to reconfigure the account once anew PM address is added
• Added a link to dependencies’ licences to the help sectionfooter

Fixed

• Updated crypto-libraries to gopenpgp v2.4.7 and go-srp v0.0.5
• Convert charset only for text/* MIME types - to ensureno attachment corruption when sending with some email clients
• Reduce unnecessary shell executions
• Syncing issues for when a new PM address is added
• Changed the wording of ‘delete this account’ dialog
• Improved manual update process (GUI changes)
• Improvements to manual update process

New

• Added keybase/go-keychain/secretservice as a new keychainhelper
• GUI changes to ‘report a problem’
• Added another proxy provider
• Improved UX for working with keychain on macOS

Fixed

• Manual update mechanism
• Windows clipboard issues (copying account details)
• Random logouts on macOS
• Error for corrupted keychain
• Bug reporting (emails send from custom domain)

New

• Improved Sentry reporting

Fixed

• Ensure messageID is properly removed from DB when it is no longerpresent on the API

New

New Bridge GUI

• Added a Status View in addition to the Main Bridge Window
• Added storage information per signed in account
• Refactor of sign in flows
• Refactor of Helps and Settings section
• Refactor of bug reports
• Refactor of Bridge update flows for beta and stable channels
• Introduced Reset Bridge feature - to clear all the local preferencesand settings
• Introduce local cache configuration
• Dark Mode for Bridge, including autodetect mechanism for systemcolour scheme
• GUI element for changing keychain (Linux)

New local cache

• Refactor of local store (caching of size, headers andbodystructure)
• Allow to store full encrypted message bodies on a disk

Other

• Update to goopenpgp 2.4.1
• Optimising sentry reporting

Fixed

• Improved retry mechanism for connecting to Proton servers
• OpenGL issue during startup for specific GPUs
• Blurry system icons with multiple monitor setup
• Bridge crashes related to unlocking local cache
• Bug with sending to ‘non-encrypted’ recipients
• Cosmetic GUI changes

New

• Bridge to only be checking and trying to unclock active keys, bothuser and address

Fixed

• Updated bbold to v1.3.6 - including Unix fixes
• Ensure ‘delete’ on ‘All Mail’ is not allowed
• Fixed behaviour for ‘append’ of external messages to Archive
• Fixed behaviour for ‘append’ of internal messages to All Mail
• Ensure ‘move’ to All Mail returns an error
• Fixed behaviour for moving/removing message to/from Spam

Fixed

• Updated crypto-libraries to gopenpgp v2.2.2 and go-srp v0.0.1
• Ensuring proper handling of updates when the user downloads thenewest version manually
• Better handling of an error for importing too large messages viaBridge
• Ensuring message packages are fully built when the list ofrecipients includes internal addresses (for the users using activedomain with Microsoft exchange)
• Fixed Uninstalling on Windows to properly clear updates
• Improvements to reusing connections - performance

Fixed

• Fixed an issues with incorrect handling of 401 server error leadingto random Bridge logouts
• Changed encoding of message/rfc822 - to better handle sending of the.msg files
• Fixed crash within RFC822 builder for invalid or empty headers
• Fixed crash within RFC822 builder for header with key length > 76chars

New

• Updated golang Secure Remote Password Protocol
• Updated crypto-libraries to gopenpgp/v2 v2.1.10
• Implemented new message parser (for imports from externalaccounts)

Fixed

• Fixed IMAP/SMTP restart in Bridge to mitigate connection issues
• Fixed unknown charset error for ‘combined’ messages
• Implemented a long-term fix for ‘invalid or missing messagesignature’ error
• Bridge not to strip PGP signatures of incoming clear textmessages
• Import of messages with malformed MIME header
• Improved parsing of message headers
• Fetching bodies of non-multipart messages
• Sync and performance improvements

Fixed

• A bug with sending encrypted emails to external contacts

Fixed

• Hotfix for error during bug reporting

Fixed

• Hotfix for crash when listing empty folder

New

• Refactor of message builder to achieve greater RFC compliance
• Implemented connection manager to improve performance during weakconnection, better handling of connection loss and other connectivityissues
• Increased the number of message fetchers to allow more parallelrequests - performance improvement
• Log changes for easier debugging (update-related)
• Prompt profile installation during Apple Mail auto-configuration onMacOS Big Sur

Fixed

• Bugs with building of message bodies/headers
• Incorrect naming format of some of the attachments
• Removed html-wrappig of non-decriptable messages - to facilitatedecryption outside Bridge and/or allow to store such messages as theyare
• Tray icon issues with multiple displays on MacOS

New

• Revise storage locations for the config files, preferences andcache
• Log improvements for easier debugging (sync issues)
• Added relevant metadata to Windows builds

Fixed

• Fixed the way Bridge interacts with Windows Firewall andDefender
• Fixed potential security vulnerability related to rpath
• Improved parsing of embedded messages
• GUI bug fixes

New

• Allow to choose which keychain is used by Bridge on Linux
• Added automatic update CLI commands
• Improved performance during slow connection
• Added IMAP requests to the logs for easier debugging

Fixed

• Fixed update notifications
• Fixed GUI freeze while switching to early update channel
• Fixed Bridge autostart
• Improved signing of update packages
• NoGUI build
• Background of GUI welcome message
• Incorrect total mailbox size displayed in Apple Mail

New

• Added desktop files and icon in Bridge repo
• Better detection of MacOS version to improve automatic AppleMailconfiguration
• Clearing cache after switching early access off

Fixed

• Better poor connection handling - added retries for starting IMAPserver after the connection was down
• Excluding updates from ‘clearing cache’
• Not allowing copying from Inbox to Sent and vice versa
• Improvements to moving messages (unlabelling folders)
• Fixed the separation of release notes for ‘early’ and ‘stable’channels

New

Introducing silent updates

• Introducing ‘early’ and ‘stable’ updates channels
• Allowing users to enable early access from within the GUI
• Adding and option to disable silent updates in settings

Changing the distribution of release notes

Performance and stability

• Implement support of UID EXPUNGE - to avoid avoid unnecessaryresync
• Improve memory usage - gopenpgp dependency updated to v2.1.3
• Reducing network traffic by caching message size and bodystructure

Adding a scroll bar to the settings tab

Fixed

• Fetch errors - introducing a stop to the imap server once there isno internet connection
• Setting up flags to avoid messages misplacement
• Inline messages incorrectly changed to attachments
• Reporting bug from accounts with empty account name
• Panic when stopping import progress during loading mailboxesinfo
• Panic when modifying addresses during changing address mode
• Panic when trying to parse a multipart/alternative section that hasno child sections
• Prevent potential loss of messages when moving to local folder andback

New

• Improvements to message parsing
• Better error handling
• Ensured better message flow by refactoring both address and dateparsing
• Improved secure connectivity checks
• Better deb packaging
• More robust error handling
• Improved package creation logic
• Refactor of sending functions to simplify code maintenance
• Added tests for package creation
• Support read confirmations
• Adding GPLv3 licence button to the GUI
• Improved testing

Fixed

• AppleMail crashes (related to timestamps)
• Sending messages from aliases in combined inbox mode
• Fedora font issues
• Ensured that conversations are properly threaded
• Fixed Linux font issues (Fedora)
• Better handling of Mime encrypted messages
• Bridge crashes related to labels handling
• GUI popup related to TLS connection error
• An issue where a random session key is included in the datapayload
• Error handling (including improved detection)
• Encoding errors
• Installation issues on linux