Exhibit 3.1

AMENDED AND RESTATED

CERTIFICATE OF FORMATION

ZIX CORPORATION,

A FOR-PROFIT CORPORATION

This Certificate of Formation is submitted for filing pursuant to the applicable provisions of the Texas Business Organizations Code.

ARTICLE I

Entity Name and Type

The name of the entity is Zix Corporation (the “Corporation”). The Corporation is a for-profit corporation.

ARTICLE II

Registered Agent and Registered Office

The registered agent of the Corporation is an organization by the name of Corporation Service Company d/b/a CSC-Lawyers Incorporating Service Company.

The business address of the registered agent and the registered office address is 211 E. 7^th, Suite 620, Austin, 78701.

ARTICLE III

Directors

The names and mailing addresses of the persons who are now serving as directors of this corporation are:

Gordon Davies, 275 Frank Tompa Dr., Waterloo, ON, N2L 0A1, Canada

Madhu Ranganathan, 275 Frank Tompa Dr., Waterloo, ON, N2L 0A1, Canada

ARTICLE IV

Authorized Shares

The total number of shares the Corporation is authorized to issue is 1,000. The par value of each of the authorized shares is $0.0001 per share.

ARTICLE V

Purpose

The Corporation is formed for the purpose of transacting any and all lawful business for which a for-profit corporation may be organized under the Texas Business Organizations Code.

ARTICLE VI

The number of directors of the Corporation shall be such as fixed by, or in the manner provided in, the Bylaws of the Corporation (the “Bylaws”). Unless, and except to the extent that, the Bylaws so require, the election of directors need not be by written ballot.

ARTICLE VII

The board of directors of the Corporation (the “Board of Directors”) may from time to time adopt, amend or repeal the Bylaws, subject to the power of the stockholders to adopt any Bylaws or to amend or repeal any Bylaws adopted, amended or repealed by the Board of Directors.

ARTICLE VIII

A. LIABILITY

No director of the Corporation shall be personally liable to the Corporation or any stockholder for monetary damages for breach of fiduciary duty as a director, except for any matter in respect of which such director shall be liable under Section 21.316 of the Texas Business Organizations Code (the “TBOC”), or any amendment thereto or shall be liable by reason that, in addition to any and all other requirements for such liability, such director (1) shall have breached the director’s duty of loyalty to the Corporation or its stockholders, (2) shall have acted in a manner involving intentional misconduct or a knowing violation of law or, in failing to act, shall have acted in a manner involving intentional misconduct or a knowing violation of law, or (3) shall have derived an improper personal benefit. If the TBOC hereafter is amended to authorize the further elimination or limitation of the liability of a director, the liability of a director of the Corporation shall be eliminated or limited to the fullest extent permitted by the TBOC, as so amended.

B. INDEMNIFICATION

Each person who was or is made a party or is threatened to be made a party to or is in any way involved in any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (hereinafter a “proceeding”), including any appeal therefrom, by reason of the fact that he or she, or a person of whom he or she is the legal representative, is or was a director or officer of the Corporation or a direct or indirect subsidiary of the Corporation, or is or was serving at the request of the Corporation as a director or officer of another entity or enterprise, or was a director or officer of a foreign or domestic corporation which

was a predecessor corporation of the Corporation or of another entity or enterprise at the request of such predecessor corporation, shall be indemnified and held harmless by the Corporation, and the Corporation shall advance all expenses incurred by any such person in defense of any such proceeding prior to its final determination, to the fullest extent authorized by the TBOC. In any proceeding against the Corporation to enforce these rights, such person shall be presumed to be entitled to indemnification and the Corporation shall have the burden of proving that such person has not met the standards of conduct for permissible indemnification set forth in the TBOC. The rights to indemnification and advancement of expenses conferred by this Article VIII shall be presumed to have been relied upon by the directors and officers of the Corporation in serving or continuing to serve the Corporation and shall be enforceable as contract rights. Such rights shall not be exclusive of any other rights to which those seeking indemnification may otherwise be entitled. The Corporation may, upon written demand presented by a director or officer of the Corporation or of a direct or indirect subsidiary of the Corporation, or by a person serving at the request of the Corporation as a director or officer of another entity or enterprise, enter into contracts to provide such persons with specified rights to indemnification, which contrasts may confer rights and protections to the maximum extent permitted by the TBOC, as amended and in effect from time to time.

If a claim under this Article VIII is not paid in full by the Corporation within sixty (60) days after a written claim has been received by the Corporation, the claimant may at any time thereafter bring suit against the Corporation to recover the unpaid amount of the claim and, if successful in whole or in part, the claimant shall be entitled to be paid also the expenses of prosecuting such claim. It shall be a defense to any such action (other than an action brought to enforce the right to be advanced expenses incurred in defending any proceeding prior to its final disposition where the required undertaking, if any, has been tendered to the Corporation) that the claimant has not met the standards of conduct which make it permissible under the TBOC for the Corporation to indemnify the claimant for the amount claimed, but the claimant shall be presumed to be entitled to indemnification and the Corporation shall have the burden of proving that the claimant has not met the standards of conduct for permissible indemnification set forth in the TBOC.

If the TBOC hereafter is amended to permit the Corporation to provide broader indemnification rights than such law permitted the Corporation to provide prior to such amendment, the indemnification rights conferred by this Article VIII shall be broadened to the fullest extent permitted by the TBOC, as so amended.

ARTICLE IX

The directors shall have powers without the assent or vote of the stockholders to fix and vary the amount to be reserved for any proper purpose; to authorize and cause to be executed mortgages and liens upon all or any part of the property of the Corporation; to determine the use and disposition of any surplus or net profits; and to fix the times for the declaration and payment of dividends.

ARTICLE X

The directors in their discretion may submit any contract or act for approval or ratification at any annual meeting of the stockholders or at any meeting of the stockholders called for the purpose of considering any such act or contract, and any contract or act that shall be approved or be ratified by the vote of the holders of a majority of the stock of the Corporation which is represented in person or by proxy at such meeting and entitled to vote thereat (provided that a lawful quorum of stockholders be there represented in person or by proxy) shall be as valid and as binding upon the Corporation and upon all the stockholders as though it had been approved or ratified by every stockholder of the Corporation, whether or not the contract or act would otherwise be open to legal attack because of directors’ interest or for any other reason.

ARTICLE XI

In addition to the powers and authorities hereinbefore or by statute expressly conferred upon them, the directors are hereby empowered to exercise all such powers and do all such acts and things as may be exercised or done by the Corporation; subject, nevertheless, to the provisions of the statutes of the State of Texas, of this Certificate, and of any Bylaws from time to time made by the stockholders; provided, however, that no Bylaws so made shall invalidate any prior act of the directors which would have been valid if such Bylaw had not been made.

ARTICLE XII

Section 21.606 of the TBOC, as amended from time to time, shall not apply to the Corporation.

ARTICLE XIII

The Corporation reserves the right to amend, alter, change or repeal any provision contained in this Certificate in the manner now or hereafter prescribed by law, and all rights and powers conferred herein on stockholders, directors and officers are subject to this reserved power.

ARTICLE XIV

Any action required by the Texas Business Organizations Code to be taken at any annual or special meeting of shareholders, or any action which may be taken at any annual or special meeting of shareholders, may be taken without a meeting, without prior notice, and without a vote, if one or more written consents setting forth the action so taken shall be signed by the holder or holders of shares having not less than the minimum number of votes that would be necessary to take such action at a meeting at which the holders of all shares entitled to vote on the action were present and voted.

ZIX CORP 8-K