<PAGE>   1
                                                                  EXHIBIT 10.16

                            NINTH AMENDMENT TO LEASE


         THIS AGREEMENT made this 10th day of November, 1999 by and between KGE
Associates, L.P., a partnership hereinafter referred to as "Landlord" and
Telemate.Net Software, Inc., a Georgia Corporation hereinafter referred to as
"Tenant".

         WHEREAS, the parties hereto made and entered into a lease agreement
dated January 28, 1992 and amended on June 11, 1993, June 22, 1994, March 30,
1995, June 14, 1996, July 26, 1996, August 2, 1996, July 16, 1998 and November
9, 1999 for certain premises (hereinafter referred to as the "Premises")
situated at Perimeter Crest Office Park, 4250 Perimeter Park Drive, Suite 200,
Atlanta, Georgia 30341.

         NOW, THEREFORE, in consideration of the mutual promises given one to
the other, the parties hereto intending to be legally bound, do hereby covenant
and agree as follows:

1.       PREMISES.

         The Premises currently being leased by Tenant under the Lease is 39,844
         square feet. With the addition of this expansion the total space leased
         by Tenant will be 46,383.

2.       EXPANSION SPACE

         a. The Premises shall be expanded to include an additional 6,539 square
         feet ("Expansion Premises") located at 4200 Perimeter Park South, Suite
         208, Atlanta, Georgia 30341. Commencement Date" means the earlier of
         (1) Landlord's delivery of possession of the Expansion Premises to
         Tenant, or (2) December 15, 1999, subject to existing tenant vacating
         the space. If by the Commencement Date Landlord has not substantially
         completed the improvements to the Expansion Premises required to be
         made hereof or if Landlord, for any reason whatsoever cannot deliver
         possession of the Expansion Premises to Tenant by the Commencement
         Date, then the Commencement Date shall be postponed (and rent herein
         provided, pro-rata to the Expansion Premises, shall not commence) until
         the earlier of either (I) the date of actual occupancy of the Expansion
         Premises by Tenant or (ii) the date immediately following the day
         Landlord has achieved substantial completion of such improvements.

         b. If, and to the extent, Landlord's substantial completion of the
         improvements to Expansion Premises pursuant to Exhibit "A" attached
         hereto is delayed due to any act or omission of Tenant or anyone acting
         under or for Tenant (any such delay being hereinafter referred to as
         "Tenant's Delay"), then the Commencement Date shall be the date
         specified above, subject to adjustment as provided therein, but without
         extension as result of Tenant's Delay; provided that from the
         Commencement Date, as so determined, until the earlier of (I) the date
         of actual occupancy of the Expansion Premises by Tenant or (ii) the
         date immediately following the date Landlord should have achieved
         substantial completion of such improvements but for Tenant's Delay,
         Tenant's obligations under this Lease shall be to the payment of any
         and all Rent due hereunder.

         c. Within five (5) days of written request by Landlord, Tenant agrees
         to execute and deliver to Landlord a Letter Agreement As To Term and
         Premises pursuant to Exhibit "B" attached and made a part hereof,
         setting forth the exact Commencement Date of the Expansion and stating
         that all tenant improvements to be constructed by Landlord have been
         substantially completed, subject to any outstanding punch-list items.

3.       ALTERATIONS AND IMPROVEMENTS

         a. Landlord will make available a Tenant Improvements Allowance
         ("Landlord's Tenant Improvement Allowance") of $3.50 per square foot of
         Expansion Space. Included as part of the Tenant Improvement Allowance
         shall be a construction management fee in the amount of five percent
         (5%) of the actual improvement cost, and all costs associated with
         architectural drawings. The design and construction of the Tenant
         Improvements shall be in accordance with working drawings to be
         approved by Landlord and Tenant prior to commencement of construction.
         The Premises will be prepared in accordance with Exhibit "A" attached
         hereto and by this reference made a part hereof ("Landlord's
         Construction"). Landlord shall have such work performed promptly,
         diligently and in a good and workmanlike manner.



<PAGE>   2

         b. Upon substantial completion of Landlord's Construction, Tenant shall
         inspect the Premises and identify "punch-list" items for Tenant's final
         acceptance. "Substantial Completion" means the Premise is reasonably
         satisfactory for acceptance and in accordance with the work depicted on
         Exhibit "A".

         c. Tenant may request substitutions, additional or extra work and/or
         materials over and above that required as depicted and described on
         Exhibit "A" hereof and/or under Tenant's approved Plans to be performed
         by Landlord, provided that the Extra Work, at Landlord's option, (I)
         shall not require the uses of contractors or types of contractors other
         than those normally engaged by Landlord in the Building; (ii) shall not
         delay completion of Landlord's Construction or the Commencement Date;
         (iii) shall be practicable and consistent with existing physical
         conditions in the Building and with plans for the Building which have
         been filed with the applicable governmental authorities having
         jurisdiction thereover; (iv) shall not impair Landlord's ability to
         perform any of Landlord's obligations hereunder or under this Lease or
         any other Agreement with respect to space in the Building; (v) shall
         not affect any portion of the Building other than the Premises; and
         (vi) any such work requested by Tenant and approved by Landlord, shall
         not cause Landlord's Construction to exceed the Tenant Improvement
         Allowance provided for herein. All Extra Work shall require the
         installation of new materials and shall be otherwise subject to
         Landlord's reasonable approval.

4.       TERM

         This Ninth Lease Amendment shall commence on the Commencement Date (as
         defined herein) and continue thirty-six (36) full calendar months (plus
         any partial calendar month if the Commencement Date is not the first
         day of the month), unless sooner terminated or extended hereunder.

5.       BASE RENTAL

         Tenant agrees to pay base rental for the Premises in accordance with
         the base rental schedules, and during the term, as defined in the Sixth
         Amendment to Lease, Seventh Amendment to Lease, Eighth Amendment to
         Lease and for this Ninth Amendment, Tenant agrees to pay base rental
         for the Expansion Premises (6,539 square feet) to Landlord during the
         term as defined in this Ninth Amendment To Lease, payable on or before
         the first day of each and every month, in advance, in accordance with
         the following schedule:

<TABLE>
<CAPTION>
         Payment Periods     Monthly Rent          Annual Base Rent    Base Rent/SF

         <S>                 <C>                   <C>                 <C>
         12/15/99-12/31/99   $4,034.14                                    $13.50
         01/01/00-12/31/00   $7,356.38             $88,276.50             $13.50
         01/01/01-12/31/01   $7,613.85             $91,366.18             $13.97
         01/01/02-12/31/02   $7,879.50             $94,553.94             $14.46
</TABLE>

6.       RENEWAL OPTION

         (a) So long as the Lease is in full force and effect, and Tenant is not
         in default in the performance of any of the covenants or terms and
         conditions of the Lease, either at the time of exercise of the option
         set forth herein or at the commencement of the renewal term set forth
         herein, Tenant is hereby granted the one-time option to renew the term
         of this Ninth Amendment to Lease (the "Renewal Option") for a period of
         three (3) additional years (the "Renewal Term"), to commence at the
         expiration of the initial term of this Ninth Amendment. The renewal of
         this Lease shall be upon the same terms and conditions of this Lease,
         except: (1) the Base Rent during the Renewal Term shall be calculated
         as set forth below based on the prevailing "Market Annual Base Rental
         Rate" (as defined below), but shall in no event be less than the Base
         Rent that Tenant is then paying under the terms of this Ninth
         Amendment; (2) Tenant shall have no option to renew this Ninth
         Amendment beyond the expiration of the Renewal Term; (3) Tenant shall
         not have the right to assign its renewal rights to any subtenant of the
         Premises or assignee of the Lease, nor may any such subtenant or
         assignee exercise or enjoy the benefit of such renewal rights: and (4)
         the leasehold improvements in the Premises will be provided in their
         then-existing condition (on an "as is" basis) at the time the Renewal
         Term commences; provided however, that Landlord may provide an
         allowance for improvements as part of Landlord's determination of the
         Market Annual Base Rental Rate. LANDLORD AGREES TO NEGOTIATE, IN GOOD
         FAITH, A TENANT IMPROVEMENT ALLOWANCE.



<PAGE>   3

                  (b) If Tenant elects to exercise the Renewal Option, Tenant
         shall do so by delivering written notice of such election to Landlord
         at least four (4) months, but no earlier than six (6) months, prior to
         the expiration of the initial term of this Ninth Amendment. Landlord
         shall advise Tenant of Landlord's determination of the Market Annual
         Base Rental Rate, as defined below, no later than thirty (30) days
         after Landlord's receipt of Tenant's notice that Tenant elects to
         exercise the Renewal Option. Landlord and Tenant shall negotiate in
         good faith to reach an agreement on the Market Annual Base Rental Rate,
         taking into consideration all factors set forth below. No later than
         thirty (30) days following Tenant's receipt of Landlord's notice
         specifying Landlord's determination of the Market Annual Base Rental
         Rate, Tenant shall provide Landlord with written notice of Tenant's
         acceptance or rejection of such determination, Tenant's failure to
         notify Landlord of acceptance or rejection shall constitute Tenant's
         acceptance of such rate. If Tenant shall fail to exercise the Renewal
         Option, or Tenant rejects Landlord's determination of the Market Annual
         Base Rental Rate, or the conditions set forth above for the exercise of
         the Renewal Option are not entirely satisfied, this Lease shall expire
         at the expiration of the initial term of this Ninth Amendment, and
         Tenant shall have no further right thereafter to renew this Lease or to
         acquire any further interest whatsoever in the Premises. If Tenant
         accepts Landlord's determination of the Market Annual Base Rental Rate
         and the lease amendment, then Tenant agrees that, within thirty (30)
         days of request by Landlord, Tenant shall execute the amendment to this
         Ninth Amendment setting forth such renewal. If for whatever reason,
         Tenant delivers notice of its election to renew the Lease to Landlord
         as provided above, but fails to execute the amendment to the Lease
         described above, Tenant shall be in default of its obligations under
         the Lease, but the Lease shall nonetheless be renewed in accordance
         with the terms hereof.

                  (c) Whenever used in this Lease, the term "Market Annual Base
         Rental Rate" shall mean Landlord's determination of the annual net
         rental rate per square foot (exclusive of expense pass-through
         additions) of net rentable area then being charged in comparable
         buildings located in the metropolitan Atlanta area for space comparable
         to the Premises, taking into consideration use, location, and/or floor
         level within the applicable building, the definition of premises
         rentable area, leasehold improvements provided, remodeling credits or
         allowances granted, quality, age and location of the applicable
         building, rental concessions (such as abatements or lease assumptions),
         the provision of free or paid unassigned parking, the time the
         particular rate under consideration became effective, size of tenant,
         relative operating expenses, relative services provided, and other
         similar factors. It is agreed that bona fide written offers to lease
         comparable space located elsewhere in the Building from third parties
         (at arm's length) may be used by Landlord as an indication of the
         Market Annual Base Rental Rate. Neither party to this Lease shall have
         the right to have a court or third party set the Market Annual Base
         Rental Rate.

7.       CANCELLATION

         This Ninth Amendment to Lease is not subject to the existing
         Cancellation Option which is in effect between Tenant and Landlord. In
         the event Tenant exercises any cancellation option set forth in any
         previous agreements, then Tenant will remain responsible for the full
         obligation of this Ninth Amendment.

8.       EXPANSION

         Tenant has no expansion rights under this Ninth Amendment to Lease

All other terms, provisions and covenants of the Lease Agreement dated January
28, 1992, as further amended, shall remain in full force and effect.

                       (Signatures on the following page)



<PAGE>   4
     IN WITNESS WHEREOF, the parties herein have hereto set their hands and
seals, in duplicate, the day and year first above written.


                                        "LANDLORD"

                                        KGE Associates, L.P.


                                        By: /s/ Elizabeth B. Hawkins
                                           ------------------------------------
                                        Its: Secretary of G.P.
                                        Date: 12/02/99


                                        "TENANT"

                                        Telemate.Net Software, Inc.


                                        By: /s/ Richard J. Pist
                                           ------------------------------------
                                        Its: Chief Financial Officer
                                        Date: 12/02/99

<PAGE>   5

                                                                     EXHIBIT "A"


                             LANDLORD'S CONSTRUCTION


TENANT'S PLANS AND SPECIFICATIONS.

Landlord and Tenant, at Landlord's sole cost and expense, subject to provisions
of Paragraph 6 hereof, shall cause to be prepared by Landlord's architect and/or
designer and/or engineer the following:

         (a) Complete, finished, detailed construction documents and
specifications for Tenant's partition layout, ceiling and other installations
for the work to be done by Landlord under Paragraph 6 hereof, subject to
limitations therein, which shall be prepared by Landlord's architect and/or
designer.

         (b)Complete mechanical and electrical plans and specifications where
necessary for the installation of air conditioning system and ductwork, heating,
electrical, plumping and other engineering plans for the work to be done by
Landlord under Paragraph 6 hereof, subject to limitations therein, which shall
be prepared by Landlord's architect and/or designer and/or engineer.

         (c) Any subsequent modifications to the construction documents and
specifications requested by Tenant.

All such plans and specifications are expressly subject to Landlord's approval
and shall comply with all applicable laws, rules, regulations and conditions of
Paragraph 6 hereof. Tenant's Plans shall be delivered to Tenant for Tenant's
approval on or before November 20, 1999 (subject to written modification between
the parties). Such approval shall not be unreasonably withheld. If Tenant shall
have reasonable grounds for withholding its approval of Tenant's Plans, Tenant,
within three (3) business days of receipt of Tenant's Plans, shall provide
Landlord with written notice of its disapproval detailing with specificity those
aspects of Tenant's Plans which Tenant disapproves. In the event Tenant fails to
provide Landlord with written notice within such three (3) business day period,
Tenant shall conclusively be deemed to have approved Tenant's Plans. In the
event Tenant provides timely written notice of its disapproval of Tenant's
Plans, within such three (3) business day period, Landlord shall amend Tenant's
Plans accordingly and deliver the amended plans to Tenant for approval. The same
procedures as for the original Tenant's Plans shall be applicable to any
amendments of Tenant's Plans under the preceding sentences. If Tenant shall fail
to approve Tenant's Plans within the times provided in this paragraph, then and
in addition to any other rights or remedies of Landlord, at Landlord's option,
may terminate this Lease Agreement and/or accelerate by the number of days of
such delay the Commencement Date. In addition, Tenant shall reimburse Landlord
for any and all expenses, losses, costs and damages suffered by Landlord and
caused by such delay. Such option shall not be exercised until at least fifteen
(15) days after the default in question.

         2. Without the prior written consent of Landlord, Tenant shall make no
changes in Tenant's Plans after approval thereof.

         3. After approval of Tenant's Plans, Landlord shall obtain from its
general contractor and submit to Tenant a quotation of the cost of improvements
of the Premises in accordance with Tenant's Plans. Upon written approval of such
quotation by Tenant, Landlord and Tenant shall be deemed to have given final
approval to Tenant's Plans, including but not limited to a date for completion
of the work required thereunder, and Landlord shall be authorized to proceed
with the improvements of the Premises in accordance with Tenant's Plans. Failure
of Tenant to reasonably approve any such quotation shall abate Landlord's
obligation to proceed with any improvements of the Premises, but shall not
postpone the Commencement Date by more than seven (7) days.

Tenant's Plans and a quotation of the cost of Tenant's extra work (as
hereinafter defined) shall be finally approved by Tenant and Landlord as
provided herein no later than November 30, 1999. A copy of Tenant's Plans as so
finally approved shall be signed and dated by both Tenant and Landlord and
delivered to Landlord for its records. A copy of the construction contract for
the improvements of the Premises in accordance with approved Tenant's Plans
shall be initialed and dated by both Tenant and Landlord and attached to this
Lease as an additional exhibit hereto.



<PAGE>   6

LANDLORD'S CONSTRUCTION

Landlord agrees, subject to limitations of Paragraph 6 hereof, at Landlord's
sole cost and expense and in conformance with Construction Documents to provide
and install the Tenant Improvements substantially in accordance with Tenant's
Plans as approved by Landlord and Tenant.

EXTRA WORK

Tenant may request substitutions, additional or extra work and/or materials over
and above that required in Paragraph 6 hereof and/or under Tenant's Plans
approved above (herein called "Extra Work") to be performed by Landlord,
provided that the Extra Work, at Landlord's option, (i) shall not require the
use of contractors or types of contractors other than those normally engaged by
Landlord in the Building; (ii) shall not delay completion of Landlord's
Construction or the Commencement Date; (iii) shall be practicable and consistent
with existing physical conditions in the Building and with plans for the
Building which have been filed with the applicable governmental authorities
having jurisdiction thereover; (iv) shall not impair Landlord's ability to
perform any of Landlord's obligations hereunder or under this Lease or any other
Agreement with respect to space in the Building; and (v) shall not affect any
portion of the Building other than the Premises. All Extra Work shall require
the installation of new materials and shall be otherwise subject to Landlord's
reasonable approval.

         2. Subject to Landlord's written consent, Tenant may request the
omission of an item of work required under the approved Tenant's Plans, provided
that such omission shall not delay the completion of the Premises, and Landlord
thereafter shall not be obligated to install same. No credit shall be granted to
Tenant for such omitted items.

PAYMENTS

As costs are incurred and bills are received by Landlord in the performance of
Extra Work, Tenant shall make periodic payments to Landlord within ten (10) days
after receipt by Tenant of a statement therefore from Landlord.

COOPERATION

All work not within the scope of the normal construction trades employed for the
Building, such as the furnishing and installing of draperies, furniture,
telephone equipment and wiring, alarm systems, and office equipment, shall be
furnished and installed by Tenant at Tenant's expense. Tenant shall adopt a
schedule in conformance with the schedule of Landlord's contractors and shall
conduct its work in such a manner as to maintain harmonious relations and as not
to interfere unreasonably with or delay the work of Landlord's contractors.
Tenant shall cause its telephone and alarm contractors to contact Landlord with
regard to installation of a telephone system in the Premises within three (3)
business days of the date Landlord commences construction of the Premises.



<PAGE>   7

                                                                     EXHIBIT "B"


KGE Associates, LP ("Landlord") and Telemate.Net Software, Inc., a Georgia
corporation ("Tenant"), do each hereby agree and certify to the other that the
Term of that certain Lease Agreement Addendum between Landlord and Tenant dated
November 10, 1999, ("Lease") commenced on the __ day of __________, _____, and
will expire on the __ day of ____________, _____, unless extended or sooner
terminated as may be provided in the Lease. Tenant hereby acknowledges that it
has accepted delivery of the Premises, containing 6,539 rentable square feet, in
"substantially complete" condition as defined in the Lease, and that said
Premises are in full compliance with all requirements of the Lease, except for
defects of which Tenant gives Landlord notice with reasonable specificity within
ten (10) business days from the Commencement Date referenced above.

IN WITNESS WHEREOF, the parties have caused their duly authorized
representatives to execute this instrument under seal as of the __ day of ___,
1999.



ATTEST:                               LANDLORD: KGE ASSOCIATES, LP


-------------------------             By:
                                         ------------------------------------

                                      Title:
                                            ---------------------------------

                                      Its:
                                          -----------------------------------

                                      Date:
                                          -----------------------------------



ATTEST:                               TENANT: TELEMATE.NET SOFTWARE, INC.

-------------------------             By:
                                         ------------------------------------

                                      Title:
                                            ---------------------------------

                                      Date:
                                         ------------------------------------

                                                    (Corporate Seal)