EXHIBIT 4.3
                                                                       EXHIBIT A



                             SECURED PROMISSORY NOTE

FORT LAUDERDALE, FLORIDA                                      U.S. $2,900,000.00
NOVEMBER 25, 2003

THIS NOTE IS A SECURITY AND IT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT
OF 1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY APPLICABLE STATE SECURITIES
LAWS. IT MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE
ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT AND
APPLICABLE LAWS OR SOME OTHER EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF
SUCH ACT AND APPLICABLE LAWS OR EXCEPT AS OTHERWISE SET FORTH HEREIN, AN OPINION
OF COUNSEL SATISFACTORY TO THE MAKER THAT SUCH REGISTRATION IS NOT REQUIRED.

         FOR VALUE RECEIVED, the undersigned, BIZCOM, U.S.A., INC., a Florida
corporation as maker hereof (the "Maker"), does hereby promise to pay, pursuant
to the terms contained herein, in lawful money of the United States of America
to the order of SOPHIA COMMUNICATIONS, INC., a Delaware corporation as payee
(the "Payee") at 2600 Douglas Road, Suite 1004, Coral Gables, FL 33134 (to the
attention of Roberto Isaias, Chairman), or at such other address as the Payee of
this Promissory Note (the "Note") shall, in writing, designate the principal sum
of TWO MILLION NINE HUNDRED THOUSAND DOLLARS ($2,900,000.00) (the "Principal
Amount") together with simple interest to accrue at the rate of four percent
(4%) per annum, payable to the Payee semi-annually on June 30th and December
31st of each year, with the Principal Amount and any unpaid interest due on or
before December 31, 2007 (the "Due Date"). There is no pre-payment penalty in
connection with any Principal Amount and/or interest payments made before the
due date therefore.

         This Note and the obligations due hereunder are secured by a pledge and
security agreement by and among SMR Management, Inc., a wholly-owned subsidiary
of the Maker (the "Subsidiary"), the Maker, and the Payee dated as of November
25, 2003 (the "Pledge and Security Agreement") which grants Payee a security
interest in the Pledged Shares (as that term is defined in the Pledge and
Security Agreement) (the "Collateral").

         Any failure on the part of Payee at any time to require the performance
by Maker of any of the terms of provisions hereof, even if known, shall in no
way affect the right thereafter to enforce the same, nor shall any failure of
Payee to insist on strict compliance with the terms and conditions hereof be
taken or held to be a waiver of any succeeding breach or of the right of Payee
to insist on strict compliance with the terms and conditions hereof.

         Maker is obligated hereunder to notify Payee in writing concurrent with
the occurrence of any such events and the failure to so notify shall also
constitute a default hereunder.

         In the event Payee fails to pay any amount due hereunder on the date it
is due or within five (5) business days after written notice of such failure
from the Payee, or in the event of any other default under this Note, at the
option of the Payee hereof: (i) the Payee may immediately declare the whole sum

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                                                      $2,900,000 Promissory Note
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<PAGE>
                                                                       EXHIBIT A

of principal and interest hereunder immediately due and payable; (ii) interest
may be charged on the amount delinquent at the maximum rate permitted by law,
effective from the date that such amount(s) shall become overdue until such
delinquent amount(s), with interest thereon at such rate, shall have been paid
in full; and/or (iii) the Payee may foreclose on the Collateral subject to the
Pledge and Security Agreement.

         If this Note is not paid when due or within five (5) business days
after written notice of such failure from the Payee, Maker promises to pay all
costs and expenses of collection, including reasonable attorneys' fees incurred
by the Payee hereof on account of such collection, whether or not suit is filed
thereon and such costs and expenses shall become part of the principal due and
owing and bear interest at the default rate provided for herein. Maker hereby
waives notice of acceptance, presentment, demand for performance, payment,
protest, notice of dishonor or nonpayment of the Note, suit or the taking of any
other action by the Payee against the Maker and the right to assert any statute
of limitations.

         All payments by Maker under this Note are to be made free and clear of
any present or future tax, levy, assessment, impost, fee, charge, restriction,
or condition whatsoever (hereinafter collectively referred to as "Tax") now or
hereafter imposed by any applicable law or regulation. Notwithstanding the
above, if Maker is compelled by law to deduct any Tax, Maker shall: (i) pay to
Payee hereof in United States Dollars an amount that, after deductions for such
Tax, equals the amount that otherwise would have been received if no Tax had
been imposed; and (ii) if requested by the Payee hereof, forward to the Payee
hereof within 90 days after each payment of such Tax, in a form acceptable to
said Payee, official documentation or certified copies thereof evidencing
payment of such Tax.

         The waiver by Payee of Maker's prompt and complete performance of, or
default under, any provision of this Note shall not operate nor be construed as
a waiver of any subsequent breach or default, and the failure by the Payee to
exercise any right or remedy that it may possess under this Note shall not
operate nor be construed as a bar to the exercise of that right or remedy upon
the occurrence of any subsequent breach or default. Maker agrees to pay when due
all documentary stamp tax which may be required in connection with the issuance
of this Note.

         This Note shall be governed by and construed solely in accordance with
the laws of the State of Florida without regard to conflict or choice of law
principles. The parties hereto agree that all actions and/or proceedings
relating directly or indirectly hereto shall be litigated solely in the state
courts and/or federal courts located in Broward County, Florida. The parties
hereto expressly consent to the jurisdiction of any such courts and to venue
therein and waive their right to a jury trial in any action or proceeding
arising directly or indirectly from this Note. The prevailing party in any
action and/or proceeding shall be entitled to recover its reasonable attorneys'
fees and costs from the other party.

         This Note cannot be modified, amended or terminated except in a written
instrument agreed to and executed by the Maker and the Payee. The Maker may not
assign this Note or any of its rights or obligations hereunder without the prior
written consent of the Payee, which consent may be withheld in the Payee's
absolute and sole discretion and without any liability to the Payee, provided,
however, that Maker shall have the right to assign its obligations hereunder to
an affiliate (as such term is defined in Rule 405 under the Securities Act) or
subsidiary of Maker without the consent of Payee, provided that any

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                                                                       EXHIBIT A

such affiliate of subsidiary shall have assets and liabilities of at least
equivalent value as the Maker as of the date hereof. This Note and any rights to
payment hereunder may not be assigned by Payee without, if required by Maker,
delivery to Maker of an opinion of counsel stating that registration under the
Securities Act is not required; provided however, this Note is freely assignable
in whole or in part by Payee or its permitted assigns described below without
the prior written consent of Maker or an opinion of counsel that registration
under the Securities Act is not required to: (i) any wholly owned subsidiary of
Payee or (ii) to any person, corporation or other entity that (x) is a
shareholder of Payee as of the date hereof; and (y) meets the definition of an
"accredited investor" under the Securities Act at the time of the assignment.

                                                    BIZCOM U.S.A., INC.



                                                    By: /s/ Hanan Klein
                                                        -------------------
                                                    Hanan Klein, President


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                                                      $2,900,000 Promissory Note
                                            Execution Copy - 11/25/2003 10:00 AM