Exhibit 10.4


                           AMENDMENT NO. 3 TO LEASE


1.   Parties.
     ------- 

     This Amendment, dated as of June 18, 1993, is between North Andover Mills
Realty ("Landlord") and FTP Software, Inc. ("Tenant").

2.   Recitals.
     -------- 

     2.1  Landlord and Tenant have entered into a Lease, dated November 19,
1991, as amended, for space at North Andover Mills in North Andover,
Massachusetts (the "Lease"). Unless otherwise defined, terms used in this
Amendment have the same meanings as those used in the Lease.

     2.2  Tenant wants to exercise its Second (and last) Expansion Option to
lease 11,024 rentable square feet of additional space located on the bottom
floor of Building 11 (the "Building 11 Space") as shown in the pages of Exhibit
"B" to the Lease, and to construct and lease a two-story addition to the open-
slab portion of the Building 3 loading dock of 1,127 rentable square feet (the
"2-Story Addition") as shown in Exhibit "AA" attached hereto and incorporated
herein by this reference (this additional space and the 2-Story Addition
collectively are called the "Second Option Space").  To accomplish this and
other matters, for Ten and No/100 Dollars ($10.00) and other good and valuable
consideration, the receipt and sufficiency of which is acknowledged, the parties
agree and the Lease is amended as follows, notwithstanding anything to the
contrary:

3.   Amendments.
     ---------- 

     3.1  (a)  In Section 1.1(c), the Premises now includes the Second Option
Space, and therefore the agreed rentable area of the Premises is increased from
94,700 square feet to 106,851 square feet.  With the inclusion of the Second
Option Space, Tenant now leases all of Buildings 3, 3A and 11 as part of the
Premises.

          (b)  In Section 1.1(f), Tenant's Percentage will be increased from
17.30% to 19.52% on the date (the "Rental Start Date") which is the earlier of:
November 1, 1993; or the date that Tenant first obtains a Certificate of
Occupancy from the Town of North Andover for the Second Option Space (which
Tenant will attempt to obtain as soon as reasonably possible).

          (c)  Base rent for the Premises allocable to the Second Option Space
will be entirely abated until the Rental Start Date.

 
               Notwithstanding anything to the contrary, starting as of the
Rental Start Date, the annual base rent for the initial Lease term for the 1,127
square foot 2-Story Addition will be One Hundred Seventy and 88/100 Dollars
($170.88) for each One Thousand and No/Dollars ($1,000.00) or portion thereof
reimbursed by Landlord to Tenant pursuant to Section 3.1(f)(ii) below for the
costs for the 2-Story Addition (prorated for any partial Lease Year), and the
parties will promptly execute an amendment to this Lease confirming this
increase when the amount of Landlord's reimbursement is determined. The failure
of either party to execute such an amendment will not alter Tenant's obligation
to pay such increase. (For example, if the reimbursements for the 2-Story
Addition total Fifty Thousand and No/100 Dollars ($50,000.00), the annual base
rent for the 2-Story Addition during the initial Lease term will be Eight
Thousand Five Hundred Forty-four and No/100 ($8,544.00), prorated for any
partial Lease Year, starting as of the Rental Start Date.) During any extension
or Option terms, the base rent per annum per square foot for the 2-Story
Addition will be at the same rate per square foot as the rest of the office
space in the Premises.

          (d)  Notwithstanding Section 3.3 of Amendment No. 1 to Lease, dated
September 1, 1992, or anything else to the contrary, upon the mutual written
agreement of Landlord and Tenant, pursuant to such agreement Landlord and Tenant
will allocate between themselves responsibility for the elevator-related
obligations as described in Section 3.3 of Amendment No. 1 (the "Elevator
Work").  If such an agreement is entered into (which neither party is required
to do), Landlord will remain responsible for the costs incurred in connection
with the Elevator Work but only up to a maximum amount specifically approved in
writing by Landlord, and Tenant will be responsible for all excess costs (if
any).  If this mutual written agreement is not entered into, then Landlord will
remain responsible for the Elevator Work, but the time within which Landlord
must provide passenger access per Section 3.3 of the Amendment No. 1 will be
extended to February 28, 1994 (subject to extension due to delays caused by
force majeure or causes beyond Landlord reasonable control).

          (e)  Tenant will be solely responsible, at its expense, for providing
all necessary work and services to: (i) construct all necessary improvements to
or that are necessary in connection with the Second Option Space (including the
2-Story Addition) to the equivalent fit, finish and specifications as the rest
of the Premises; and (ii) perform the Elevator Work if Tenant becomes
responsible for it as provided in Section 3.1(d) above. All work will be done
diligently and in a good and workmanlike manner, using new materials and in
compliance with all applicable Laws and the terms of this Lease. Tenant's work
will include, without limitation, all necessary hookups, connections and tie-
ins, all necessary drawings, plans and engineering, and securing all necessary
permits, inspections, approvals and a final Certificate of Occupancy from the
Town of North Andover. Tenant's work and the plans and specifications therefor
will be subject to the prior review and approval of and coordination and
supervision by Landlord or its representatives and will be performed so as not
to damage the rest of the Project or its Systems and Equipment.

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          (f)  Landlord will reimburse to Tenant (i) a construction allowance of
up to One Hundred Seventy-Three Thousand Six Hundred Twenty-eight and No/100
Dollars ($173,628.00) to reimburse Tenant for all costs incurred and paid for by
Tenant directly related to the construction of the space on the bottom floor of
Building 11, (ii) a construction allowance of up to One Hundred Twenty Thousand
and No/100 Dollars ($120,000.00) to reimburse Tenant for all costs incurred and
paid for by Tenant directly related to the construction of the 2-Story Addition,
and (iii) a construction allowance up to the maximum amount agreed to by
Landlord as described in Section 3.1(d) above to reimburse Tenant for all costs
incurred and paid for by Tenant directly related to the Elevator Work if Tenant
becomes responsible for the Elevator Work per Section 3.1(d) above (and Tenant
will submit paid invoices against work in place for all reimbursements
requested) within 30 days after the following conditions have been satisfied,
and provided that Tenant is not in default under the Lease: (x) Tenant's work
has been fully paid for and completed in accordance with the plans therefor and
the terms of this Lease and Tenant and its architect (or other representative)
and contractors, so certify to Landlord; (y) Tenant delivers final and
unconditional lien releases from all contractors, subcontractors, laborers and
suppliers and certifies that all liens that have been or could be filed have
been discharged of record or waived, and the lien filing periods have run; and
(z) Tenant delivers to Landlord the final Certificate of Occupancy from the Town
of North Andover and a set of "as built" plans and drawings for the Second
Option Space, and final inspections and approvals of the Elevator Work from all
required governmental authorities (if Tenant becomes responsible for Elevator
Work as described in Section 3.1(d) above). Tenant will account separately for
the costs incurred in Subsections (i), (ii) and (iii) above. If Landlord does
not reimburse the construction allowances to Tenant when required, from and
after the date that reimbursement was required the unpaid portion of the
construction allowance that is then due will bear interest until paid at a rate
per annum equal to the Wells Fargo Bank prime rate of interest form time to time
plus 3%.

4.   No Other Changes.
     ---------------- 

     Except as set forth above, the Lease remains unchanged and in full force
and effect and there are no defaults by Landlord or Tenant thereunder.

     IN WITNESS WHEREOF, intending to be legally bound, the parties have
executed this Amendment under seal as of the date first set forth above.
 

WITNESS:                                FTP SOFTWARE, INC.
 
/s/ Edward J. Rosner                    By:  /s/ Stev Knowles
- ------------------------                   --------------------------
Name printed:                           Name:  Stev Knowles
Edward J. Rosner                        Title: Vice President
                                        Authorized Signatory

                                      -3-

 
WITNESS:                                By: /s/ Nancy L. Connor
                                           --------------------------
                                        Name:   Nancy L. Connor
/s/ Edward J. Rosner                    Title:  Secretary
- ------------------------                Authorized Signatory
Name Printed:
Edward J. Rosner

                                        NORTH ANDOVER MILLS REALTY
WITNESS:
                                        By: Niuna-North Andover, Inc.,
                                        general partner
                        
/s/ David Zirkle                        By:  /s/ John Kusmiersky
- ------------------------                   --------------------------
Name Printed:                           Name:   John Kusmiersky
                                        Title:  President
                                        Authorized Signatory



WITNESS:                                By: CIIF Associates, a Massachusetts
                                             partnership, general partner
/s/ Thomas W. Mazza, Jr.
- ------------------------                     By: Copley Advisors, Inc., managing
Name Printed:                                      general partner
Thomas W. Mazza
                                                   By: /s/ Charles A. Valentino
                                                      --------------------------
                                                   Name:   Charles A. Valentino
                                                   Title:  Managing Director
                                                   Authorized Signatory

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