It has also agreed to pay a maximum of €4.95m, dependant on NP6's financial performance for the years ending December 2007 and December 2008. This will be paid half in cash and half in shares.
Lionel Thain, IPT's chief executive, said: "NP6 is an established and successful company, well known for the quality of its products and the high standard of service it provides to its customers. We look forward to being able to offer these services to all of the group's customers."
NP6's three founders -- Stephane Zittoun, Cedric Notario and Jerome Laplace -- will remain at the newly acquired business.
Zittoun, the firm's president, said: "NP6 and IPT are both market leading companies in their territories. We are delighted to form part of an enlarged group with a shared strategy of becoming the clear leader in email marketing services in Europe."
IPT has over 1,000 clients in the UK and France, including American Express, Dell, Littlewoods, Procter & Gamble, AXA, Tesco, Scottish Power and Renault.
NP6 operates out of Bordeaux. It was founded in 1999 and has over 140 clients. These include Cdiscount, ChateauOnline, Fortuneo Direct Finance, Cofinoga and Cultura.com. It reported annual revenues of €3.2m in 2006.