Hey Sheryl.
I have access to a similar (I presume) leads program through Perfect Wedding Guide.
In three years I've only reached out twice.
The first time was with a large postcard mailing. We spent about $500 on really nice postcards and postage, and it probably took hours of time to address them all. The second time was via "email blast", directly through the leads program.
The results:
We got several inquiries as a direct result of the postcards, and actually earned a booking. However, the email blast didn't even get us an inquiry.
I have recognized to myself that I often ignore companies who market via email. It is much less personal, and people have an inherent initial distrust of the sender.
If you're going to do it at all, do the postcards. Keep them simple and elegant, with a clear message and a CALL TO ACTION (ask/tell the recipient to do something...such as visit your website, or email you with "promo code XYZ" in the subject line).
Good luck!