How to send a mail to a serviceA@mydomain.com address without picking up each persons in this service

[Xavier SANVOISIN <xsanvoisin@diot.fr>]

I need to configre a service in which I would have the possibility to use an attribute which would pick up all my users emails for this service.

Example :
For my domain "mydomain.com" , I have several services, service A, service B...
In the Service A, I have several persons who all have an email address.
And I want to send a mail to all the users of this service A.
Instead of searching and wondering who is in this service, I'd like to have the possibility to send a mail to serviceA@mydomain.com, in which all my persons of this group would have their email address.

Hom could I do that, please ?