Delegate {1} does not have SendAs permissions for principal {0}, but it does have SendOnBehalfOf permissions. If this is ...

Delegate {1} does not have SendAs permissions for principal {0}, but it does have SendOnBehalfOf permissions. If this is not desired, please have the the principal assign the necessary SendAs permissions and remove the SendOnBehalfOf permissions.  Note that have both permissions will default to using SendOnBehalfOf permissions.