Yes, GSA has several methods of informing GSA contract vendors about upcoming projects and sales opportunities. Federal buyers use GSA Advantage to learn about GSA Vendors. Federal Agencies use GSA's E-buy to post RFQ's and communicate upcoming needs to GSA schedule contractors. Federal buyer use E-buy to post RFQ's strictly limited to GSA contractors.
But that does not mean that successful vendors sit back and wait to receive a lot of opportunities via e-mail. The most successful GSA contractors actively market their goods and services to Federal agencies.