Bottomline (EPAY) 10-Q 2003 Q3 Quarterly report

Exhibit 99.1

CERTIFICATION 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 quarterly report on Form 10-Q of Bottomline Technologies (de), Inc. (the “Company”) for the period ended March 31, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, Joseph L. Mullen, President and Chief Executive Officer of the Company, hereby certifies, pursuant to 18 U.S.C. Section 1350, that:

(1) the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: May 14, 2003	By:	/s/    JOSEPH L. MULLEN
		Joseph L. Mullen President and Chief Executive Officer

A signed original of this written statement required by Section 906 has been provided to Bottomline Technologies (de), Inc. and will be retained by Bottomline Technologies (de), Inc. and furnished to the Securities and Exchange Commission or its staff upon request.