Absolutely WRONG!!!! Deutsche Post DHL sold its Postbank business TO Deutsche Bank. Carefully re-read your own link, especially this part:
Postbank had belonged to the Deutsche Post Group since 1999. As part of its focus on its core competencies - mail and global logistics - Deutsche Post DHL initiated its gradual withdrawal from the financial-services business in September 2008 with an agreement to sell its Postbank stake to Deutsche Bank.
Once again, Deutsche Bank and DHL are two totally separate companies with only the name "Deutsche" in common, just like American Airlines and American Express have "American" in common.
Really are you not reading the article
"We were able to withdraw from the banking business at a very difficult time for the financial industry at attractive conditions," said Frank Appel, the CEO of Deutsche Post DHL . "Since then, we have been able to channel all of our energies into successfully carrying out our mail operations and driving the implementation of our growth strategy in our global logistics business. Under the umbrella of Deutsche Bank, Postbank will be able to continue its positive evolution. Even after the sale, we will continue to maintain a close working relationship with Postbank in our retail-outlet business."