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                                                                    EXHIBIT 31.1

                                  CERTIFICATION

I, William E. McGlashan, Jr., certify that:

    1.  I have reviewed this quarterly report on Form 10-Q of Critical Path,
Inc.

    2.  Based on my knowledge, this report does not contain any untrue statement
of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this report.

    3.  Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations and cash flows of the registrant as
of, and for, the periods presented in this report.

    4.  The registrant's other certifying officers and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

        a) Designed such disclosure controls and procedures, or caused such
    disclosure controls and procedures to be designed under our supervision, to
    ensure that material information relating to the registrant, including its
    consolidated subsidiaries, is made known to us by others within those
    entities, particularly during the period in which this report is being
    prepared;

        b) Evaluated the effectiveness of the registrant's disclosure controls
    and procedures and presented in this report our conclusions about the
    effectiveness of the disclosure controls and procedures, as of the end of
    the period covered by this report based on such evaluation; and

        c) Disclosed in this report any change in the registrant's internal
    control over financial reporting that occurred during the registrant's most
    recent fiscal quarter that has materially affected, or is reasonably likely
    to materially affect, the registrant's internal control over financial
    reporting; and

    5.  The registrant's other certifying officers and I have disclosed, based
on our most recent evaluation of internal control over financial reporting, to
the registrant's auditors and the audit committee of registrant's board of
directors (or persons performing the equivalent functions):

        a) All significant deficiencies and material weaknesses in the design or
    operation of internal control over financial reporting which are reasonably
    likely to adversely affect the registrant's ability to record, process,
    summarize and report financial information; and

        b) Any fraud, whether or not material, that involves management or other
    employees who have a significant role in the registrant's internal control
    over financial reporting.

Date: August 14, 2003                    /s/ William E. McGlashan, Jr.
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                                                 William E. McGlashan, Jr.
                                          Chief Executive Officer and Chairman