Name: event_extra_params
Type: BITFIELD
Allowed-Values: bodyStructure clientAddress diskUsed flagNames
 messageContent messageSize messages modseq service timestamp uidnext
 vnd.cmu.midset vnd.cmu.unseenMessages vnd.cmu.envelope vnd.cmu.sessionId
 vnd.cmu.mailboxACL vnd.cmu.mbtype vnd.cmu.davFilename vnd.cmu.davUid
 vnd.fastmail.clientId vnd.fastmail.sessionId vnd.fastmail.convExists
 vnd.fastmail.convUnseen vnd.fastmail.cid vnd.fastmail.counters
 vnd.fastmail.jmapEmail vnd.fastmail.jmapStates vnd.cmu.emailid
 vnd.cmu.threadid vnd.cmu.visibleUsers
Default-Value: timestamp
Last-Modified: 3.12.0

Space-separated list of extra parameters to add to any appropriated event.
