<PAGE>

                                                                   Exhibit 10.56

                                              April 29, 2004


Silicon Valley Bank
One Newton Executive Park, Suite 200
2221 Washington Street
Newton, MA 02462

     RE: LOAN ARRANGEMENT WITH NAVISITE, INC., CLEARBLUE TECHNOLOGIES
         MANAGEMENT, INC., AVASTA, INC., CONXION CORPORATION, AND
         INTREPID ACQUISITION CORP.

Gentlemen:

     Reference is made to that certain loan arrangement (the "Loan Arrangement")
by and among (i) SILICON VALLEY BANK, a California-chartered bank, with its
principal place of business at 3003 Tasman Drive, Santa Clara, California 95054
and with a loan production office located at One Newton Executive Park, Suite
200, 2221 Washington Street, Newton, Massachusetts 02462, doing business under
the name "Silicon Valley East" ("Bank") and (ii) NAVISITE, INC., a Delaware
corporation, CLEARBLUE TECHNOLOGIES MANAGEMENT, INC., a Delaware corporation,
AVASTA, INC., a California corporation, CONXION CORPORATION, a California
corporation, and INTREPID ACQUISITION CORP., a Delaware corporation
(collectively, "Borrower"), evidenced by, among other documents, a certain
Accounts Receivable Financing Agreement by and among Borrowers and Bank dated as
of May 27, 2003, as amended by a certain First Loan Modification Agreement dated
as of January 30, 2004, and as further amended by a certain Second Loan
Modification Agreement dated as of April 29, 2004 (as amended, the "Loan
Agreement").

     Borrowers have notified Bank that, on or before August 1, 2004, the
following wholly-owned subsidiaries of Navisite intend to merge into one or more
of the Borrowers such that, after giving effect to such mergers, such Borrowers
will be the surviving legal entities (the "Mergers"): (a) ClearBlue
Technologies/Chicago-Wells, Inc., (b) ClearBlue Technologies/Las Vegas, Inc.,
(c) ClearBlue Technologies/Milwaukee, Inc., (d) ClearBlue Technologies/Los
Angeles, Inc., (e) ClearBlue Technologies/Oakbrook, Inc., (f) ClearBlue
Technologies/Vienna, Inc., (g) ClearBlue Technologies/New York, Inc., (h)
ClearBlue Technologies/Santa Clara, Inc., (i) ClearBlue Technologies/Dallas,
Inc., and (j) ClearBlue Technologies/San Francisco, Inc.

     Borrowers hereby covenant and agree that: (i) Borrowers shall cause the
Mergers to occur, and deliver to Bank evidence of same satisfactory to Bank, and
(ii) deliver evidence to Bank, satisfactory to Bank, that the assets of the
Subsidiaries are free and clear of all liens, no later than September 1, 2004.

<PAGE>
     This letter shall take effect as a sealed instrument under the laws of the
Commonwealth of Massachusetts as of the date hereof.


BORROWER:                                BANK:

NAVISITE, INC.                           SILICON VALLEY BANK, doing business as
                                         SILICON VALLEY EAST

By: /s/ Kenneth Drake                    By: /s/ illegible
    ---------------------------------        -----------------------------------

Title: Secretary                         Title: SVP
       ------------------------------           --------------------------------

CLEARBLUE TECHNOLOGIES MANAGEMENT, INC.

By /s/ Kenneth Drake
   ----------------------------------

Title Secretary
      -------------------------------

AVASTA, INC.

By /s/ Kenneth Drake
   ----------------------------------

Title Secretary
      ------------------------------

CONXION CORPORATION

By /s/ Kenneth Drake
   ----------------------------------

Title Secretary
      -------------------------------

INTREPID ACQUISITION CORP.

By /s/ Kenneth Drake
   ----------------------------------

Title Secretary
      -------------------------------