I have an organization which has 10 employees.

In Exchange, I created a list of 75 contacts as well as a few mailing lists (example: Executive members).

a) I would like to share the list of 75 contacts with each of the 10 employees.

b) When one person updates information on a contact sheet, I would like it to be shared with everyone who has access to the mailing list in which this contact is listed.

Is there a way to set this up so that these processes can be completed automatically?

Assistance is much appreciated.