Personal communications should be included in the text of your document, but they should not be included in your bibliography. It is recommended that permission is sought from the source/author of a personal communication if you wish to include quotes in your text. The details you need to include when referencing in text are:
• the date of the communication;
• whether the communication was in oral or written form;
• the affiliation of the person might also be included to better establish the relevance and authority of the citation (recommended).
Conversation
In a conversation with a colleague from the School of Theology (Michael Owen 2002, oral communication, 7th August)...
Letter
As stated in a letter from B.J. Samuels, MD, in July 2002...
...the new research projects in anthropology were discussed in an email from Paul Smith, received on February 5, 2000.
Do not include the email address of the author.