DavMail

Maintenance release focused on Graph API improvements and network resilience. Implemented native people search for GAL, room booking support, and improved recurrence/timezone handling. Enhanced IMAP with UID EXPUNGE, UNKEYWORD and RFC 3501 date compliance. Added self-signed certificate generation, improved SWT stability, and hardened error handling across all protocols.

Graph

• Graph: fix for https://github.com/mguessan/davmail/issues/522 user reports transactionId is not always unique, reimplement EWS approach based on calendaruid, keep transactionId to block duplicate creation over Graph
• Graph: merge https://github.com/mguessan/davmail/pull/527, Use transactionId as backup in getCalendarUid - #527
• Graph: merge https://github.com/mguessan/davmail/pull/528 Unilaterally set calendaruid for events
• Graph: prepare orderBy in GraphRequestBuilder
• Graph: implement workaround for out of sync calendar by fetching event by iCalUid, force isExpired check on session creation to validate token, use caldavPastDelay to build search task filter
• Graph: cleanup from audit
• Graph: fix https://github.com/mguessan/davmail/issues/532 O365Graph: refreshToken requests Outlook resource when enableOidc=false
• Graph: fix for https://github.com/mguessan/davmail/issues/535, change urlcompnameToIdMap cache key to use EML form, fixes task GET/PUT/DELETE by client item name
• Graph: fix for https://github.com/mguessan/davmail/issues/536, set X-MICROSOFT-SKYPETEAMSMEETINGURL from onlineMeeting joinUrl
• Graph: fix for https://github.com/mguessan/davmail/issues/536, preserve link href in convertHtmlToText
• Graph: improve timezone conversion in DateUtil to avoid unwanted warnings
• Graph: ensure permanentUrlToImapUidMap is always populated
• Graph: detect closed http client in isExpired()
• Graph: initiate room booking implementation, change paging size on event search
• Graph: fix https://github.com/mguessan/davmail/issues/548, do not lookup inbox for event messages over graph, rely on O365 to handle auto scheduling automatically
• Graph: check token before returning session, detect invalid token (edge case after an EWS -> Graph switch and clear stored refresh token
• Graph: improve handleThrottling, retry on transient graph endpoint errors
• Graph: Change isExpired logic to rethrow exception on network error
• Graph: randomize retry delay to avoid thundering herd on concurrent retries
• Graph: fix recurrence UNTIL value, use timezone already fixed in DTSTART to match original event timezone instead of user timezone, see https://github.com/mguessan/davmail/issues/549
• Graph: rename X-MICROSOFT-ISRESPONSEREQUESTED, see https://github.com/mguessan/davmail/issues/549
• Graph: use native graph field for CLASS/sensitivity instead of the MAPI property see https://github.com/mguessan/davmail/issues/549
• Graph: fetch PidLidOwnerCriticalChange on meetings to get correct owner timestamp see https://github.com/mguessan/davmail/issues/549
• Graph: Fix for https://github.com/mguessan/davmail/issues/558 IMAP Connection Closes when Trying to Delete Mail Item that is Already Gone, workaround for Graph bug returning 403 forbidden for deleted messages
• Graph: interim fix for https://github.com/mguessan/davmail/issues/556 Support Exchange Online Archive in O365Graph mode
• Graph: handle isCancelled property on events, set STATUS to CANCELLED on occurrence
• Graph: update checkConfig to hit Graph endpoint instead of legacy EWS endpoint
• Graph: replace legacy A-Z search with native people search
• Graph: set size limit in galFind matching ldap size limit
• Graph: improve galFind search, leverage people search api to reduce redundant API calls
• Graph: Use Directory source only to avoid duplicates with personal contacts which are already returned separately by the LDAP layer via searchContacts
• Graph: fix https://github.com/mguessan/davmail/issues/566 normalize display name to short constants for consistency across backends
• Graph: fix for https://github.com/mguessan/davmail/issues/563, force old VCARD 3 content with outdated macOS 27 Contacts application
• Graph: grabbed fix from https://github.com/mguessan/davmail/pull/568, rename optString to optSectionString and fix issue on item name map

EWS

• EWS: Detect EWS disabled on tenant
• EWS: merge https://github.com/mguessan/davmail/pull/530, rebuild occurrences from occurrence items, do not trust Exchange to properly update MIME content
• EWS: drop urlcompname on contacts, prefer itemId instead as more reliable id
• EWS: implement room booking handling over EWS, based on Resources collection and cutype
• EWS: fetch startTimeZone to provide a failover for localized tzid not available in timezones map, should fix https://github.com/mguessan/davmail/issues/542
• EWS: make default CUTYPE room on attendee resources
• EWS: implement null filtering on specific EWS calls that request starttimezone, remove � and � from xml content
• EWS: improve null character filtering implementation, add unit tests
• EWS: initiate davmail.caldavAutoSchedule deprecation, Exchange always handle scheduling events automatically
• EWS: fix for https://github.com/mguessan/davmail/issues/564 do not send ChangeKey in SavedItemFolderId, not needed and may cause ErrorCannotCreateContactInNonContactFolder, ErrorCannotCreateCalendarItemInNonCalendarFolder

O365

• O365: fix https://github.com/mguessan/davmail/issues/520, print number matching in headless mode
• O365: just rethrow UnknownHostException in refresh token, do not convert to NetworkDownException

CalDAV

• Caldav: refactor ICSBufferedWriter to remove recurion and avoid stack overflow with very long lines
• CalDAV: fix https://github.com/mguessan/davmail/issues/533 update ICSCalendarValidator, drop invalid characters instead of replacing with space
• Caldav: fix https://github.com/mguessan/davmail/issues/550, default event participant to required per RFC 5545 section 3.2.16
• Caldav: merge https://github.com/mguessan/davmail/pull/540 report sub calendars as httpd/unix-directory in calendar listings
• Caldav: improve network error handling
• Caldav: fix nested response end
• Caldav: over both Graph and EWS, do not fail on missing occurrence id, may just be a cancelled occurrence, see https://github.com/mguessan/davmail/issues/559
• Caldav: merge change ICSCalendarValidator from https://github.com/mguessan/davmail/pull/560
• Caldav: send empty response on root HEAD request
• Caldav: avoid warning on Thunderbird caldav probing
• Caldav: no need to dump stack trace on client connection closed
• Caldav: fix for https://github.com/mguessan/davmail/issues/562, send principal-URL property if requested on root, drop old isIcal5 check
• Caldav: fix https://github.com/mguessan/davmail/issues/543 invalid duration value in alarm

LDAP

• LDAP: lookup LDAP_TO_CONTACT_ATTRIBUTE_MAP before CONTACT_ATTRIBUTES

IMAP

• IMAP: improve message thread error handling
• IMAP: improve network down detection over IMAP, return *BYE instead of *BAD
• IMAP: force refresh on MOVE to send EXPUNGE notifications, see https://github.com/mguessan/davmail/issues/546
• IMAP: merge https://github.com/mguessan/davmail/pull/545 implement UID expunge
• IMAP: merge changes from https://github.com/mguessan/davmail/pull/521, implement UNKEYWORD
• IMAP: remove unnecessary IMAP messages content debug logging
• IMAP: merge changes from https://github.com/mguessan/davmail/pull/521, align SINCE/BEFORE/ON with RFC 3501 INTERNALDATE
• IMAP: merge changes from https://github.com/mguessan/davmail/pull/521, additional test cases
• IMAP: ensure we don't silently network error during fetch
• IMAP: Avoid infinite loop waiting on IDLE when client disconnects
• IMAP: properly send * BYE on UnknownHostException
• IMAP: cleanup from audit
• IMAP: improve message fetch logging

SMTP

• SMTP: improve network issues error handling

SWT

• SWT: fix race condition in display initialization, see https://github.com/mguessan/davmail/issues/544
• SWT: fix deadlock in switchIcon and resetIcon methods, use asyncExec

Enhancements

• Merge https://github.com/mguessan/davmail/pull/531, Prefer NTLM over Basic auth against on-prem Exchange when both are offered
• Implement HttpClientAdapter.isClosed()
• Log which network interface is up in network down detection logic
• Revert unwanted change in winrun4j config
• Implement a new -generateCert command line option to generate a self-signed PKCS12 certificate
• Add generate certificate button to settings window, will help users setup TLS with self-signed certificates.
• Cleanup from audit

Documentation

• Doc: update README contribute section to point to GitHub, we receive all user contributions there anyway
• Doc: remove review no longer online, add newer reviews and articles

Test

• Test: need to force O365Graph mode in AbstractDavMailTestCase