2.2 Message Syntax

An E-mail object can be created and modified by clients and servers. Except where noted, this section defines constraints to which both clients and servers adhere when operating on E-mail objects.

Clients operate on E-mail objects by using the Message and Attachment Object Protocol, which is specified in [MS-OXCMSG]. How a server operates on E-mail objects is implementation-dependent, but the results of any such operations are to be exposed to clients in a manner that is consistent with the Email Object Protocol.

Unless otherwise specified, E-mail objects adhere to all property constraints specified in [MS-OXPROPS] and all property constraints specified in [MS-OXCMSG]. An E-mail object can also contain other properties, as specified in [MS-OXPROPS], but these properties have no impact on this protocol.

When a property is referred to as "read-only for the client", the server returns an error and ignores any request to change the value of that property.

Message senders are identified by the from properties and the sender properties on an E-mail object. In general, the from properties and the sender properties will identify the same messaging user; for example, the e-mail message appears to have been sent by the actual sender of the e-mail message. In some cases, however, an e-mail message is sent by one user (the actual sender) on behalf of another user (the represented sender). In this case, the from properties identify the represented sender, and the sender properties identify the actual sender.

Message object properties can be considered as belonging to certain groups based on the type of messaging sub-object they represent. The first four groups represent actual senders, represented senders, represented recipients, and actual recipients. Other properties correspond to the Body and Subject sub-objects of a message. A separate class of properties is used to specify the To recipients, carbon copy (Cc) recipients, and blind carbon copy (Bcc) recipients of an e-mail message. The remaining properties that do not fall under these groups are used to specify either other subobjects related to message management, or to control the method or timing of message delivery.

An actual recipient is the owner of the mailbox that receives the e-mail message. The following properties are associated with actual recipients:

  • PidTagMessageRecipientMe (section 2.2.1.19)

  • PidTagReceivedByAddressType (section 2.2.1.36)

  • PidTagReceivedByEmailAddress (section 2.2.1.37)

  • PidTagReceivedByEntryId (section 2.2.1.38)

  • PidTagReceivedByName (section 2.2.1.39)

  • PidTagReceivedBySearchKey (section 2.2.1.40)

  • PidTagRecipientType (section 2.2.3.1)

The represented sender of an e-mail message is the messaging user or user agent on whose behalf the e-mail message was sent (or will be sent). The following from properties are associated only with the represented sender:

  • PidTagSentRepresentingAddressType (section 2.2.1.54)

  • PidTagSentRepresentingEmailAddress (section 2.2.1.55)

  • PidTagSentRepresentingEntryId (section 2.2.1.56)

  • PidTagSentRepresentingName (section 2.2.1.57)

  • PidTagSentRepresentingSearchKey (section 2.2.1.58)

  • PidTagOriginalSentRepresentingAddressType (section 2.2.2.11)

  • PidTagOriginalSentRepresentingEmailAddress (section 2.2.2.12)

  • PidTagOriginalSentRepresentingEntryId (section 2.2.2.13)

  • PidTagOriginalSentRepresentingName (section 2.2.2.14)

  • PidTagOriginalSentRepresentingSearchKey (section 2.2.2.15)

The actual sender is the owner of the mailbox that sent (or will send) the e-mail message. The following from properties are associated with the actual sender:

  • PidTagSenderAddressType (section 2.2.1.48)

  • PidTagSenderEmailAddress (section 2.2.1.49)

  • PidTagSenderEntryId (section 2.2.1.50)

  • PidTagSenderName (section 2.2.1.51)

  • PidTagSenderSearchKey (section 2.2.1.52)

  • PidTagOriginalSenderAddressType (section 2.2.2.6)

  • PidTagOriginalSenderEmailAddress (section 2.2.2.7)

  • PidTagOriginalSenderEntryId (section 2.2.2.8)

  • PidTagOriginalSenderName (section 2.2.2.9)

  • PidTagOriginalSenderSearchKey (section 2.2.2.10)

The recipients (2) subobject is a collection of recipients (2), each of which is a messaging user to whom e-mail messages will be (or have been) delivered. As with senders, there are two types of recipients (2): represented recipients and actual recipients. Within each of these types, there are three subclasses of recipients (2) for an e-mail message: To recipients, Cc recipients, and Bcc recipients.

A represented recipient is the messaging user or user agent on whose behalf the e-mail message is being received. The following recipient properties are associated with represented recipients:

  • PidTagReceivedRepresentingAddressType (section 2.2.1.23)

  • PidTagReceivedRepresentingEmailAddress (section 2.2.1.24)

  • PidTagReceivedRepresentingEntryId (section 2.2.1.25)

  • PidTagReceivedRepresentingName (section 2.2.1.26)

  • PidTagReceivedRepresentingSearchKey (section 2.2.1.27)

Another set of from properties is used to identify three subclasses of recipients (2) for an e-mail message: To recipients, Cc recipients, and Bcc recipients.

The following from properties are associated with To recipients:

  • PidTagDisplayTo (section 2.2.1.9)

  • PidTagMessageToMe (section 2.2.1.17)

  • PidTagOriginalDisplayTo (section 2.2.2.3)

The following from properties are associated with Cc recipients:

  • PidTagDisplayCc (section 2.2.1.8)

  • PidTagMessageCcMe (section 2.2.1.18)

  • PidTagOriginalDisplayCc (section 2.2.2.4)

The following from properties are associated with Bcc recipients:

  • PidTagDisplayBcc (section 2.2.1.7)

  • PidTagOriginalDisplayBcc (section 2.2.2.5)

The Subject subobject is a short text string that is intended to inform a recipient (1) as to the contents or purpose of the e-mail message. The following properties are associated with the subject:

  • PidTagNormalizedSubject ([MS-OXCMSG] section 2.2.1.10)

  • PidTagSubjectPrefix (section 2.2.1.60)

  • PidTagOriginalSubject (section 2.2.2.16)

The Body subobject, as specified in [MS-OXBBODY], contains the main contents of the e-mail message. The following properties are associated with the body:

  • PidTagBlockStatus (section 2.2.1.1)

  • PidTagBody ([MS-OXCMSG] section 2.2.1.56.1)

  • PidTagBodyHtml ([MS-OXCMSG] section 2.2.1.56.3)

  • PidTagRtfCompressed ([MS-OXCMSG] section 2.2.1.56.4)

  • PidTagRtfInSync ([MS-OXCMSG] section 2.2.1.56.5)

  • PidTagMessageEditorFormat (section 2.2.1.78)

Many properties that are not associated with the preceding core E-mail objects are included with an e-mail message in support of other particular subobjects. The following subobjects, along with their associated properties, fall into this category:

  • Conversations

    • PidTagConversationIndex ([MS-OXOCFG] section 2.2.8.8)

    • PidTagConversationTopic (section 2.2.1.5)

      If an e-mail message in the conversation thread is given a new subject, this e-mail message starts the new conversation thread with a new value for both the PidTagConversationTopic and PidTagConversationIndex properties.

  • Client Options

    • PidTagIconIndex (section 2.2.1.10)

    • PidTagMessageClass ([MS-OXCMSG] section 2.2.1.3)

    • PidTagReadReceiptRequested (section 2.2.1.29)

    • PidTagReadReceiptEntryId (section 2.2.2.26)

    • PidTagReadReceiptSearchKey (section 2.2.2.28)

    • PidTagOriginalSensitivity (section 2.2.1.22)

    • PidTagRecipientReassignmentProhibited (section 2.2.1.42)

    • PidTagReplyRequested (section 2.2.1.45)

    • PidTagResponseRequested (section 2.2.1.46)

    • PidTagReplyRecipientEntries (section 2.2.1.43)

    • PidTagReplyRecipientNames (section 2.2.1.44)

    • PidLidAutoProcessState (section 2.2.1.73)

    • PidLidVerbStream (section 2.2.1.74)

    • PidLidVerbResponse (section 2.2.1.75)

Finally, the following properties are set by an e-mail client or server to control how messages are delivered:

  • PidTagExpiryTime (section 2.2.3.7)

  • PidTagInternetMessageId (section 2.2.1.12)

  • PidTagOriginatorDeliveryReportRequested (section 2.2.1.20)

  • PidTagOriginatorNonDeliveryReportRequested (section 2.2.1.21)

  • PidTagSendRichInfo ([MS-OXOABK] section 2.2.3.18)

  • PidTagTransportMessageHeaders (section 2.2.1.61)

  • PidTagOriginalDeliveryTime (section 2.2.2.2)

  • PidTagOriginalSubmitTime (section 2.2.2.17)

  • PidTagParentKey (section 2.2.2.18)

  • PidTagReportTag (section 2.2.2.22)

  • PidTagReportText (section 2.2.2.23)

  • PidTagMessageFlags ([MS-OXCMSG] section 2.2.1.6)

  • PidTagMessageDeliveryTime (section 2.2.3.9)

  • PidTagDeferredSendNumber (section 2.2.3.2)

  • PidTagDeferredSendUnits (section 2.2.3.3)

  • PidTagDeferredSendTime (section 2.2.3.4)

  • PidTagExpiryNumber (section 2.2.3.5)

  • PidTagExpiryUnits (section 2.2.3.6)

Show: