The marketing drive, which is called 'Partners for Growth' and showcases how Royal Mail has helped business customers, breaks in October across TV, digital and press.
The ads will explain how businesses such as gift provider Hotel Chocolat and online lingerie retailer Figleaves.com have successfully used the mailer's services.
Royal Mail will also flag up a dedicated area of its website, which will provide a series of case studies on its clients.
Since the deregulation of postal services, Royal Mail has faced stiff competition from rivals such as Business Post. Royal Mail hopes the campaign, created by Abbott Mead Vickers BBDO, will also raise staff morale by proving its business model has a future.
Royal Mail has largely abandoned broad ad campaigns targeting consumers, a strategy it used throughout the 80s and 90s, because 90% of its revenue now comes from businesses.
Last week, however, the company launched a direct marketing initiative that involved sending branded goods to consumers.
After an initial stage of test mailing, 30,000 people have signed up to receive the boxes. The test mailing, to just under 1000 ABC1 males, included a small tub of Play-Doh from Sony Bravia.
Car maker Nissan provided a branded box of soap crayons, while Nintendo Wii provided a sweatband.