# Check for any users tracking an email by External Reference ID

Endpoint: POST /v1/emails/threads/byExternalReferenceId
Version: 1.0

## Request fields (application/json-patch+json):

  - `externalReferenceIds` (array)

## Response 200 fields (text/plain):

  - `value` (array,null)

  - `value.externalReferenceId` (string,null)

  - `value.tracking` (array,null)

  - `value.tracking.trackedByUserId` (string,null)

  - `value.tracking.trackedOnDateTimeUtc` (string,null)

  - `value.tracking.trackedToRecord` (object)

  - `value.tracking.trackedToRecord.recordType` (string)
    Options:MatterMilestoneTaskOrganisationContractFileInvoiceBatchKnowledgeArticleFolderFolderTemplateKnowledgeLibraryInboundEmailUserMessageThreadTimelineEntryMatterStatusContractStatusMessageComment
    Enum: "Matter", "Milestone", "Task", "Organisation", "Contract", "File", "InvoiceBatch", "KnowledgeArticle", "Folder", "FolderTemplate", "KnowledgeLibrary", "InboundEmail", "User", "MessageThread", "TimelineEntry", "MatterStatus", "ContractStatus", "Message", "Comment"

  - `value.tracking.trackedToRecord.recordId` (integer)