We have a requirement to send .ics meeting invite in email to customers. We have set the meeting details on the corr page and used the OOTB function "@(Pega-ProCom:Default).SendEmailMessage(myStepPage)" to send meeting invites. But emails are failed to send due to below error 

"Caught javax.mail.AuthenticationFailedException, 535 Authentication failed: The provided authorization grant is invalid, expired, or revoked"

Emails are sent fine with the function "pega_integrationengine_default.SendEmailMessage(myStepPage);" but it doesn't create the meeting invites.

Any clue on how to resolve this error??