Error when sending e-mails...

Hello experts,

We are currently testing our report that lets users create new customers and then send e-mails

to specfified user's e-mail address located in a custom table. Now, we always get this error:

Database error for <ADDR_PERS_COMP_COMM_GET> <0>

We cannot pinpoint exactly whatcauses this error. Really need help on this guys and thank you very much.