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Exhibit 10.1

SECURED PROMISSORY NOTE

$750,000   Mountain View, California
October 11, 2001

    FOR VALUE RECEIVED, Robert DeVincenzi ("Borrower"), an employee of Ditech
Communications Corporation, a Delaware corporation ("Company"), hereby
unconditionally promises to pay to the order of Company, in lawful money of the
United States of America and in immediately available funds, the principal sum
of Seven Hundred Fifty Thousand Dollars ($750,000) (the "Loan") together with
accrued and unpaid interest thereon, each due and payable on the dates and in
the manner set forth below.

    The intent of the parties is that the purpose of this Secured Promissory
Note ("Note") is not for consumer, family or household purposes.

    This Note is executed and delivered in connection with that certain Account
Control Agreement dated as of October 11, 2001 and executed by and among
Borrower, Company, and Smith Barney, Inc. (as the same may from time to time be
amended, modified or supplemented or restated, the "Agreement"). Additional
rights of Company are set forth in the Agreement. All capitalized terms used
herein and not otherwise defined herein shall have the respective meanings given
to them in the Agreement.

    1.  Definitions.  As used in this Note, the following terms shall have the
following definitions:

    "Business Day" shall mean any day that is not a Saturday, Sunday, or other
day that is a national holiday.

    "Cause" shall mean Borrower's (i) conviction of any crime involving
dishonesty; (ii) participation in any fraud against the Company; (iii) serious
misconduct or willful violation of the Company's policies, as determined by
Company in its sole discretion; or (iv) conduct which in the good faith and
reasonable determination of the Company demonstrates gross unfitness to serve.
Physical (excluding self-inflicted incapacitation) or mental disability shall
not constitute Cause.

    "Good Reason" shall mean Borrower's good faith reason for electing to
terminate his employment with Company because, in Borrower's reasonable
discretion, Company has directed Borrower to violate a reasonable and customary
code of business ethics so as to cause loss, damage, or injury to either
(i) Borrower's reputation, (ii) the Company, or (iii) the property or reputation
of a client of the Company.

    "Lien" shall mean any mortgage, lien, deed of trust, charge, pledge,
security interest or other encumbrance.

    "Obligations" shall mean the Loan, interest, fees, charges, expenses and
attorney's fees and costs and other amounts, obligations, covenants, and duties
owing by Borrower to Company of any kind and description pursuant to or
evidenced by this Note and the Agreement, whether direct or indirect, absolute
or contingent, due or to become due, now existing or hereafter arising.

    "UCC" shall mean the Uniform Commercial Code as the same may from time to
time be in effect in the state of California.

    2.  Principal Repayment.  The outstanding principal amount of the Loan shall
be due and payable on November 1, 2004 (the "Maturity Date").

    3.  Interest Rate.  Borrower further promises to pay interest on the
outstanding principal amount hereof from the date hereof until payment in full,
which interest shall be payable at the rate of four and fifty-nine hundredths
percent (4.59%) per annum or the maximum rate permissible by law (which under
the laws of the State of California shall be deemed to be the laws relating to
permissible rates of interest on commercial loans), whichever is less (the
"Interest Rate"). Interest shall be due and payable

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on the Maturity Date, compounds annually, and shall be calculated on the basis
of a 360-day year for the actual number of days elapsed.

    Any principal repayment or interest payment on the Loan hereunder not paid
when due, whether at stated maturity, by acceleration or otherwise, shall bear
interest at a rate equal to the Interest Rate plus two percent (2.0%).

    4.  Place/Manner of Payment.  All amounts payable hereunder shall be payable
at the office of Company as set forth below unless another place of payment
shall be specified in writing by Company.

825 E. Middlefield Road
Mountain View, CA 94043
Attention: Chief Financial Officer

    5.  Application of Payments.  Payment on this Note shall be applied first to
accrued interest, if any, and thereafter to the outstanding principal balance
hereof.

    6.  Prepayment.  At any time, upon two (2) Business Days' prior written
notice to Company, Borrower shall have the option to prepay, without payment or
premium, the relevant principal amount due and owing hereunder, together with
all interest accrued and unpaid on the amount to be prepaid as of the date of
such prepayment, by paying a minimum amount of $50,000 or any multiple of
$10,000 in excess thereof. Notwithstanding any partial prepayment made
hereunder, the terms of this Note shall remain unchanged.

    7.  Secured Note.  The full amount of this Note is secured by the Assets
identified and described in the Agreement. Borrower hereby grants to Company a
valid, first priority, continuing security interest in all the presently
existing or hereafter acquired Assets received into securities account number
81905401-1-5 maintained with Smith Barney, Inc. to secure prompt, full and
complete payment of the Obligations.

    8.  Representations and Warranties.  Borrower hereby represents and warrants
to Company that:

    (a) Borrower is the sole holder of record and the sole beneficial owner of
all Assets pledged to Company by Borrower under Section 7 of this Note, free and
clear of any (i) adverse claim, as defined in Section 8102(a)(1) of the UCC, and
(ii) Liens, except for (x) the security interest granted to Company under this
Note, and (y) Liens resulting from commissions, fees, or charges based upon
transactions in the Account pursuant to the Section 2 of the Agreement
(collectively, "Permitted Liens").

    (b) No effective security agreement, financing statement, equivalent
security or lien instrument, control agreement, or continuation statement
covering all or any part of the Assets exists, except for this Note and the
Agreement.

    (c) This Note creates a legal and valid security interest on and in all of
the Assets in which Borrower now has rights and all other actions necessary or
desirable to perfect and protect such security interest have been duly taken.
Accordingly, Company has a fully perfected first priority security interest in
all of the Assets in which Borrower now has rights subject only to Permitted
Liens. This Note and the Agreement will create a legal and valid and fully
perfected first priority security interest in the Assets in which Borrower later
acquires rights, when Borrower acquires those rights subject only to Permitted
Liens.

    9.  Covenants.  Borrower covenants and agrees with Company that from and
after the date of this Note and until the Obligations have been performed and
paid in full:

    (a) Disposition of Assets.  Borrower shall not sell, lease, transfer or
otherwise dispose of any of the Assets (each, a "Disposition"), or attempt or
contract to do so, other than a Disposition approved of in writing by the
Company prior to such Disposition.

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    (b) Limitation on Liens on Assets.  Borrower shall not, directly or
indirectly, create, permit or suffer to exist, and shall defend the Assets
against and take such other action as is necessary to remove, any Lien on the
Assets, except Permitted Liens.

    (c) Further Assurances.  At any time and from time to time, upon the written
request of Company, and at the sole expense of Borrower, Borrower shall promptly
and duly execute and deliver any and all such further instruments and documents
and take such further action as Company may deem necessary or desirable to
obtain the full benefits of this Note, including, without limitation, executing,
delivering and causing to be filed any financing or continuation statements
(including "in lieu" continuation statements) under the UCC with respect to the
security interests granted hereby. Borrower also hereby authorizes Company to
file any such financing or continuation statement (including "in lieu"
continuation statements) without the signature of Borrower.

    10. Default.  Each of the following events shall be an "Event of Default"
hereunder:

    (a) Borrower fails to pay timely any of the principal amount due under this
Note on the date the same becomes due and payable or any accrued interest or
other amounts due under this Note on the date the same becomes due and payable;

    (b) Borrower files a petition or action for relief under any bankruptcy,
insolvency or moratorium law or any other law for the relief of, or relating to,
debtors, now or hereafter in effect, or makes any assignment for the benefit of
creditors or takes any action in furtherance of any of the foregoing;

    (c) An involuntary petition is filed against Borrower (unless such petition
is dismissed or discharged within sixty (60) days) under any bankruptcy statute
now or hereafter in effect, or a custodian, receiver, trustee, assignee for the
benefit of creditors (or other similar official) is appointed to take
possession, custody or control of any property of Borrower;

    (d) Any breach by Borrower of Section 9(a); provided, however Borrower shall
have ten (10) Business Days to cure such breach by providing to the Company a
written investment proposal satisfactory to the Company in its sole discretion
designating cash or other securities to be deposited or maintained in the
account subject to the Agreement to replace the Assets disposed of by Borrower;

    (e) Any breach by Borrower of any warranty, representation, or covenant
(other than Section 9(a)) set forth herein or in the Agreement;

    (f)  Any report, information, or notice made to, obtained, or received by
Company at any time after the date hereof indicating that Company's security
interest in the Assets is not prior to all other security interests or other
interests reflected in such report, information, or notice;

    (g) Borrower's employment by or association with Company is terminated for
Cause or at Borrower's election for other than Good Reason; or

    (h) Death of Borrower.

    Upon the occurrence of an Event of Default hereunder, all unpaid principal,
accrued interest and other amounts owing hereunder shall automatically be
immediately due, payable and collectible by Company pursuant to applicable law.
Company shall have all rights and may exercise any remedies available to it
under law, successively or concurrently.

    11. Waiver.  Borrower waives presentment and demand for payment, notice of
dishonor, protest and notice of protest of this Note, and shall pay all costs of
collection when incurred, including, without limitation, reasonable attorneys'
fees, costs and other expenses.

    The right to plead any and all statutes of limitations as a defense to any
demands hereunder is hereby waived to the full extent permitted by law.

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    12. Governing Law.  This Note shall be governed by, and construed and
enforced in accordance with, the laws of the State of California, excluding
conflict of laws principles that would cause the application of laws of any
other jurisdiction.

    13. General Indemnity.  Borrower shall indemnify, defend, and hold Company
and each of its respective officers, directors, employees, counsel, agents, and
attorneys-in-fact (each, an "Indemnified Person") harmless from and against any
and all liabilities, obligations, losses, damages, penalties, actions,
judgments, suits, costs, charges, expenses, and disbursements (including
reasonable attorneys' costs) of any kind or nature whatsoever of or initiated by
Borrower, his beneficiaries, or heirs which may at any time (including at any
time following repayment or termination of the Loan) be imposed on, incurred by
or asserted against any such Indemnified Person in any way relating to or
arising out of this Note or the Agreement, or any document contemplated by or
referred to herein or therein, or the transactions contemplated hereby or
thereby, or any action taken or omitted by such Indemnified Person under or in
connection with any of the foregoing, including with respect to any
investigation, litigation, or proceeding (including any insolvency proceeding or
appellate proceeding) related to or arising out of this Note or the Agreement,
whether or not any Indemnified Person is a party thereto.

    14. Successors and Assigns.  The provisions of this Note shall inure to the
benefit of and be binding on any successor to Borrower and shall extend to any
holder hereof. Borrower shall not, without the prior written consent of holder,
assign any of its rights or obligations hereunder.

BORROWER:
 
/s/ Robert DeVincenzi

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ROBERT DEVINCENZI
ACCEPTED AND AGREED:
 
 
COMPANY
 
DITECH COMMUNICATIONS CORPORATION,
a Delaware corporation
 
 
/s/ William J. Tamblyn

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Name: William J. Tamblyn
Title: Chief Financial Officer

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Exhibit 10.1