Open Text (OTEX) SC 13D EASYLINK SERVICES INTERNATIONAL / OPEN TEXT ownership change

Exhibit 1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned hereby (i) agree to the joint filing with all other Reporting Persons (as such term is defined in the statement on Schedule 13D described below) of a statement on Schedule 13D (including amendments thereto) with respect to the Class A Common Stock, par value $0.01 per share, of EasyLink Services International Corporation and (ii) agree that this Agreement be included as an Exhibit to such joint filing. This Agreement may be executed in any number of counterparts all of which taken together shall constitute one and the same instrument.

Dated: May 9, 2012

OPEN TEXT CORPORATION

By: /s/ Gordon A. Davies

                             Name: Gordon A. Davies

Title: Chief Legal Officer and

Corporate Secretary

EPIC ACQUISITION SUB INC.

By: /s/ Gordon A. Davies

                             Name: Gordon A. Davies

Title: Secretary