36 C.F.R. § 1236.22 : Parks, Forests, and Public Property — NATIONAL ARCHIVES AND RECORDS ADMINISTRATION — RECORDS MANAGEMENT — ELECTRONIC RECORDS MANAGEMENT — ADDITIONAL REQUIREMENTS FOR ELECTRONIC RECORDS — What are the additional requirements for managing electronic mail records?

(a) Agencies must issue instructions to staff on the following retention and management requirements for electronic mail records:
(1) The names of sender and all addressee(s) and date the message was sent must be preserved for each electronic mail record in order for the context of the message to be understood. The agency may determine that other metadata is needed to meet agency business needs, e.g., receipt information.
(2) Attachments to electronic mail messages that are an integral part of the record must be preserved as part of the electronic mail record or linked to the electronic mail record with other related records.
(3) If the electronic mail system identifies users by codes or nicknames or identifies addressees only by the name of a distribution list, retain the intelligent or full names on directories or distributions lists to ensure identification of the sender and addressee(s) of messages that are records.
(4) Some e-mail systems provide calendars and task lists for users. These may meet the definition of Federal record. Calendars that meet the definition of Federal records are to be managed in accordance with the provisions of GRS 23, Item 5.
(5) Draft documents that are circulated on electronic mail systems may be records if they meet the criteria specified in 36 CFR 1222.10(b) of this subchapter.
(b) Agencies that allow employees to send and receive official electronic mail messages using a system not operated by the agency must ensure that Federal records sent or received on such systems are preserved in the appropriate agency recordkeeping system.
(c) Agencies may elect to manage electronic mail records with very short-term NARA-approved retention periods (transitory records with a very short-term retention period of 180 days or less as provided by GRS 23, Item 7, or by a NARA-approved agency records schedule) on the electronic mail system itself, without the need to copy the record to a paper or electronic recordkeeping system, provided that:
(1) Users do not delete the messages before the expiration of the NARA-approved retention period, and
(2) The system's automatic deletion rules ensure preservation of the records until the expiration of the NARA-approved retention period.
(d) Except for those electronic mail records within the scope of paragraph (c) of this section:
(1) Agencies must not use an electronic mail system to store the recordkeeping copy of electronic mail messages identified as Federal records unless that system has all of the features specified in §1236.20(b) of this part.
(2) If the electronic mail system is not designed to be a recordkeeping system, agencies must instruct staff on how to copy Federal records from the electronic mail system to a recordkeeping system.
(e) Agencies that retain permanent electronic mail records scheduled for transfer to the National Archives must either store them in a format and on a medium that conforms to the requirements concerning transfer at 36 CFR part 1235 or maintain the ability to convert the records to the required format and medium at the time transfer is scheduled.
(f) Agencies that maintain paper recordkeeping systems must print and file their electronic mail records with the related transmission and receipt data specified by the agency's electronic mail instructions.

36 C.F.R. §1236.22