dovecot updated to 2.2.28, pigeonhole to 0.4.17
    auth: Support OAUTHBEARER and XOAUTH2 mechanisms. Also support them
      in lib-dsasl for client side.
    imap: SEARCH/SORT may have assert-crashed in
      client_check_command_hangs
    imap: FETCH X-MAILBOX may have assert-crashed in virtual mailboxes.
    search: Using NOT n:* or NOT UID n:* wasn't handled correctly
    fts: fts_autoindex_exclude = \Special-use caused crashes
    doveadm-server: Fix leaks and other problems when process is reused
      for multiple requests (service_count != 1)
    sdbox: Fix assert-crash on mailbox create race
    lda/lmtp: deliver_log_format values weren't entirely correct if Sieve
      was used. especially %{storage_id} was broken.
    imapsieve plugin: Fixed assert failure occurring when used with virtual
      mailboxes.
    doveadm sieve plugin: Fixed crash when setting Sieve script via attribute's
      string value.