Office 2013 and later

Returns the account stamp of the account that delivered the message.

Associated properties:


Property set:


Long ID (LID):


Data type:



General messaging

This property should contain the same value that is returned from the Account Management API property PROP_ACCT_STAMP for the account that delivered the message.

Message store providers expose this named property and PidLidInternetAccountName so that the following actions occur:

  • When a user clicks Reply to All in an email message, Outlook removes the email address that is associated with the account and is stamped on the message from the recipient list of the reply. This behavior occurs unless this email address is the sender of the original message.

  • By default, Outlook sends replies and forwarded messages through the account that is stamped on the original message.

Usually, the Outlook Protocol Manager delivers messages, and Outlook sets the PidLidInternetAccountName and PidLidInternetAccountStamp properties to indicate the account that delivered the message. However, if a message store is tightly coupled with a transport, the Outlook Protocol Manager does not deliver messages and Outlook cannot set these properties. In this scenario, Outlook calls the IMAPIProp::GetIDsFromNames function. If the message store provider wants to expose these named properties, it should implement IMAPIProp::GetIDsFromNames and return property tags through the output parameter lppPropTags. Outlook can then call the IMAPIProp::GetProps method by using these property tags, and the message store provider can return the account name and stamp of the desired account.

To support these named properties, store providers should expect Outlook to use IMAPIProp::GetIDsFromNames to obtain the property tag for this property. Outlook specifies the following values for the MAPINAMEID structure that corresponds to this named property, which is passed as part of the array pointed at by the input parameter lppPropNames of IMAPIProp::GetIDsFromNames.