EXHIBIT 32.1 CERTIFICATION BY CHIEF EXECUTIVE OFFICER PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Annual Report of Genesis Energy, L.P. (the "Partnership") on Form 10-K for the year ended December 31, 2003 (the "Report") filed with the Securities and Exchange Commission on March 29, 2004, I, Mark J. Gorman, President and Chief Executive Officer of Genesis Energy, Inc., the general partner of the Partnership, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that: (1) the Partnership's Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934 as amended; and (2) the information contained in the Form 10-K fairly presents, in all material respects, the financial condition and results of operations of the Partnership. March 29, 2004 /s/ Mark J. Gorman -------------------------------------- Mark J. Gorman President and Chief Executive Officer, Genesis Energy, Inc.