These are some useful links for research on email data:

Communities, groups, and mailing lists:

• Email Research Community
• Email Research on Google Groups
• Email Research on LinkedIn
• The Enron Email Corpus Mailing List

People who do research on email:

• Prof. William W. Cohen
• Prof. Douglas W. Oard
• Prof. Andrew McCallum
• Dr. Vitor R. Carvalho
• Dr. Mark Dredze
• Dr. Andrew Lampert
• Dr. Michal Laclavik
• Dr. Simon Scerri

Email data processing tools:

• MinorThird: A Java tool for storing text, annotating text, and learning to extract entities and categorize text
• Ontea: Pattern-based Semantic Annotation Platform
• Jangada: An API for signature block extraction and reply-to extraction.
• Ciranda: An application that predicts the Email-Acts (or email speech-Acts) of email messages.
• Zebra: Segmenting and Classifying Email Text

Email research conferences and workshops:

• Messaging and Web of Data: Private meets Public (Email2012 Workshop)
• International Workshop on Next Trends in Email (NextMail'11)
• Conference on Email and Anti-Spam (CEAS 2010, CEAS 2011)
• MIT Spam Conference(SC2007, SC2008, SC2009, SC2010)
• International Workshop on E-mails in E-commerce and Enterprise Context (E3C 2009)
• Workshop on Enhanced Messaging (EMAIL-2008)
• Email Archive Visualization Workshop (EmailViz-2005)