An Open Letter to the Sendmail Open Source Community, from Proofpoint and Sendmail Inc.

As part of Proofpoint's acquisition of Sendmail, Inc*., I am happy to
welcome the Sendmail Open Source Community into the Proofpoint family.

Some of you may be wondering whether Proofpoint will continue to support
the sendmail open source Mail Transfer Agent.

The answer is an unequivocal -yes-.

Proofpoint Inc. (NASDAQ:PFPT) is a leading security-as-a-service provider
that focuses on solutions for email, threat protection, compliance,
archiving & governance, and secure communications.

Organizations around the world depend on Proofpoint's expertise, patented
technologies and on-demand delivery system to protect against phishing,
malware and spam, safeguard privacy, encrypt sensitive information, and
archive and govern messages and critical enterprise information.

Within the context of our association with Cloud and Big Data
technologies, we have made use of (and members of our team participate in,
and attempt to contribute towards the development of) various open source
initiatives ever since our inception as a company. We were engaged with
sendmail before we were engaged with Sendmail, and we absolutely intend to
continue - if not increase - that activity with this commercial
acquisition.

We all appreciate the opportunity to continue participating in the
community, and continuing to work together towards a more robust, secure
global messaging infrastructure.

Sincerely yours,

Gary

Gary Steele
CEO, Proofpoint
*More information about the acquisition may be found on our website at
http://www.proofpoint.com/about-us/press-releases/10012013.php