We have a SQL 2008R2 Reporting server, on this server there a few reports where users can add a subscription to receive a timed email.
When the subscription is made by me or another admin then the mailing works perfectly to every user.
If the subscription is made by a standard windows user with reporting admin privileges then the mailing fails with the following error: Failure sending mail: The report server has encountered a configuration error. Mail will not be resent.
I've tried modifying the rights of one user to sysadmin level on SQL without a result, tried an open relay smtp server in the reporting settings without any result.
I think that this will be a security problem but I don't know where to start or look, anyone a suggestion?