The activity, which was created by Meteorite, kicked off this week and is targeting 14,000 contacts at advertisers and agencies.
The mail pack carries the theme of a "DM seedbox", reflecting the variety of products and services available to marketers. A set of "seed booklets" advises recipients on how to "grow your own direct mail".
Over the last 12 months, Royal Mail has introduced new services including Personalised Integrated Media, a branded CD mailer that was developed in conjunction with Sony DADC and aims to combine the strengths of digital and DM; and Sensory Mail, developed with BrandSense to produce mailing campaigns that engage the five human senses.
The Royal Mail DM activity is being supported by ads in marketing media.
Antony Miller, Royal Mail's head of media development, said: "As the media owner, Royal Mail is the expert in getting the most out of direct mail campaigns, and we have developed a comprehensive range of solutions to make the lives of those in the media industry much easier - some of which are free.
"We can essentially provide a one-stop shop for advice, consultancy and insight into getting the most out of direct mail. This pack provides us with a great opportunity to build knowledge of our products and services with the very people they have been developed to assist -- hands-on brand managers and account directors who are carrying our direct marketing activity on a daily basis."