"The SMTP address has no mailbox associated with it." error for connecting to a Shared Mailbox using a Service Account via EWS

Issue

What can cause the following error when testing the mailbox connection with EWS protocol to a Shared Mailbox using a Service Account?

Connection to EWS mailbox https://<Domain>/EWS/Exchange.asmx cannot be established.
Error message:The SMTP address has no mailbox associated with it.

How can I resolve this issue?

Cause

This error can be caused by not specifying the full domain in the User Name.

For Example, the User Name is specified as: xyz\ServAcct\SharedMailbox

Solution

To resolve this issue, specify the full domain in the User Name.

For Example, the User Name should be specified in one of the formats below: DOMAIN\user\SharedMailbox@domain.com DOMAIN\user@domain.com\SharedMailbox@domain.com (in this case, DOMAIN is ignored and @domain.com is used) DOMAIN\user\SharedMailbox (will work if DOMAIN == domain.com, which is not always the case)

Level of Complexity

Easy

Applies to  

References

Add any references to other internal or external articles

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