Exhibit 23.1 CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the Infinity Logistics Corporation 1998 Stock Option Plan of our report dated January 28, 2000, with respect to the financial statements of E-Stamp Corporation included in the Annual Report on Form 10-K for the year ended December 31, 1999. /s/ ERNST & YOUNG LLP Palo Alto, California July 28, 2000