Why return incorrect email address format from OutLook when getting from Graph SDK?

Question

This is the result that I try to get from Microsoft Graph SDK By using this API https://graph.microsoft.com/v1.0/me/messages/AAMkAGVmMDEzMTM4LTZmYWUtNDdkNC1hMDZiLTU1OGY5OTZhYmY4OABGAAAAAAAiQ8W967B7TKBjgx9rVEURBwAiIsqMbYjsT5e-T7KzowPTAAAAAAEMAAAiIsqMbYjsT5e-T7KzowPTAASoXUT3AAA=
Value obtained from graph:

"sender":{      
     "emailAddress":{ 

                "name":"Adele Vance", 

                "address":"/O=EXCHANGELABS/OU=EXCHANGE ADMINISTRATIVE GROUP   
     (FYDIBOHF23SPDLT)/CN=RECIPIENTS/CN=06CCDC60A87A4DA8B961910A1A0C8C22-03B298BA-05" 

     }
 }

What is this and how to convert it to email address? /O=EXCHANGELABS/OU=EXCHANGE ADMINISTRATIVE GROUP (FYDIBOHF23SPDLT)/CN=RECIPIENTS/CN=06CCDC60A87A4DA8B961910A1A0C8C22-03B298BA-05

Answer 1

Hi there Jackie Dinh

Thanks for using QandA platform

This is an Exchange LegacyDN format, not a standard email address. \i think when the sender's address is from an on-premises environment and isn't properly resolved.

try using the sender.emailAddress.address field after enabling InternetMessageHeaders, or use the Graph API /users/{id} or /contacts lookup by LegacyDN .

If this helps kindly accept the answer thanks much.

Answer 2

This is the LegacyExchangeDN, used internally by Exchange. It's also used by Outlook for replying to messages, and common cause of IMCAEX-related NDRs.

It's perfectly valid for sending messages via Exchange Online, including via the Graph API's methods. But the attribute itself is not exposed via the Graph API methods, such as /me or /users, so you cannot use the Graph to convert it to a "regular" email address. The only supported method to do that would be Exchange PowerShell, where you can query for recipients based on the LegacyExchangeDN value, and then "resolve" it to one of the email addresses:

Get-Recipient "LegacyExchangeDN " | select -ExpandProperty EmailAddresses

If you want to learn more about this attribute, here's a nice article from Michel: https://www.enowsoftware.com/solutions-engine/exchange-center/bid/151745/the-attribute-the-myth-the-legacyexchangedn