EXHIBIT 8.1

                      [PILLSBURY WINTHROP LLP LETTERHEAD]

                                 March 4, 2004

Critical Path, Inc.
350 The Embarcadero
San Francisco, CA 94105

     Re:  Registration Statement on Form S-3 (File No. 333-111559)

Ladies and Gentlemen:

     We have acted as counsel to Critical Path, Inc., a California corporation
("Critical Path"), in connection with the preparation of a Registration
Statement on Form S-3 (File No. 333-111559) filed with the Securities and
Exchange Commission on December 24, 2003, as amended (the "Registration
Statement"), with respect to the distribution to holders of Critical Path common
stock on the record date of rights to purchase Series E preferred stock (the
"Rights Offering"). All capitalized terms used herein, but not defined herein,
shall have the meanings ascribed to them in the Registration Statement.

     In our opinion, the discussion set forth under the heading "Material United
States Federal Income Tax Consequences" in the Registration Statement
constitutes, in all material respects, a fair and accurate summary of the United
States federal income tax consequences generally applicable to a holder of
Critical Path common stock who receives subscription rights pursuant to the
Rights Offering.

     Except as set forth above, we express no other opinion. This opinion is
expressed as of the date hereof, and we disclaim any undertaking to advise you
of subsequent changes relating to matters considered herein or of any subsequent
changes in applicable law.

     We hereby consent to the filing of this opinion as Exhibit 8.1 to the
Registration Statement and to the use of our name under the captions "Material
United States Federal Income Tax Consequences" and "Legal Matters" in the
Registration Statement and in the Prospectus included therein. In giving this
consent, we do not thereby admit that we are within the category of persons
whose consent is required under Section 7 of the Act or the rules and
regulations of the Securities and Exchange Commission promulgated thereunder.


                                          Very truly yours,

                                          /s/ PILLSBURY WINTHROP LLP