M co-founder Hugh Morrison leads the account and began working with the German postal company last week. Morrison and M consultant Kevin Soady lead a six-strong team handling media relations and financial communications around Deutsche Post's offer.
Deutsche Post and Exel, which retains The Maitland Consultancy, first met last Monday and confirmed merger talks last week.
If Deutsche Post secures Exel, it would put the latter's executives in charge of a new business, which would also comprise Deutsche Post's UK subsidiary DHL. On an international scale the merger would create the world's biggest logistics company.
Deutsche Post hopes the acquisition will help it diversify its business away from its core postal and packing operation.
But the media are already speculating that a rival company might try and spoil the tie-up.
American package delivery company UPS has appointed investment bank Goldman Sachs to explore whether it should make a counter-offer and trigger a potential bidding war for the business.
Exel is already the largest standalone provider of supply chain management and freight forwarding services in the world. It moves freight in 14 of the 15 largest economies and its customers include 75 per cent of the world's 250 largest non-financial companies. This includes running warehouses for Marks & Spencer and shipping car parts for DaimlerChrysler.
Last year, Exel's annual turnover was £6.3bn. The company employs 110,000 people in more than 130 countries.