Personal communications should be cited in the text of your document, but they should not be included in your reference list. 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;
• it is recommended that the affiliation of the person is also included to better establish the relevance and authority of the citation.
In a conversation with a colleague from the School of Population Health (Jameson LI 2002, oral communication, 7th August)...
As stated in a letter from B.J. Samuels, MD, in July 2002...
In text: In an email from Professor Peter Smith (email@example.com) in February 2000 (1) ...
1. Smith P. New research projects in gastroenterology [Internet]. E-mail to Matthew Hart (firstname.lastname@example.org) 2000 Feb 5 [cited 2000 Mar 17].