All other user are able to send notification out from a workflow. Except this one user, he is new. In XRM, he has been added like the other users. I am not sure why we are getting error for his. See below.
Hello,
User has to allow to send emails other users on behalf of his account. Recheck following article:
https://ashwaniashwin.wordpress.com/2013/02/24/you-cannot-send-e-mail-as-the-selected-user-the-selected-user-has-not-allowed-this-or-you-do-not-have-sufficient-privileges-to-do-so-error-crm-2011/
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