See this example properly formatted in the QUT Cite tool.
(A. Author, personal communication, Month DD, Year)
Author stated… (personal communication, Month DD, Year)
It was confirmed that this organism was present (Professor R. Collins, personal communication, April 16, 2004).
Personal communications are not included in the reference list, as these materials cannot be traced by the reader.
Personal communications include private letters, memos, personally conducted, unpublished interviews, and electronic messages (not publically archived).