Companies that send out direct mail as part of their communications with consumers in the UK may be paying higher prices in the future. Post & Parcel notes that Royal Mail is calling for regulators to do away with the price caps and allow second-class stamps to go from 36p to 55p -- a more than 50 percent rise.

Some groups are striking out against the proposal. The Forum of Private Business (FPB) sent a letter to Ofcom (which regulates Royal Mail) asking that it reject the request to increase second-class stamp prices by up to 50 percent.

Jan Bennett, FPB's head of campaigns, said in the letter that small businesses often use the service and would be seriously impacted by price increases.

"Constantly increasing stamp prices is no way to reform a service, and could actually reduce the number of customers using the postal service. Royal Mail needs to improve its efficiency, but not by crude price hikes," she said.

Regardless of whether the hikes go through, direct mailers can adopt contact data quality software to clear their customer lists of outdated entries, duplicate addresses and other issues. This can help reduce the number of pieces that are sent unnecessarily, thus driving down the total cost of a mailing campaign.