File names are made up of the following strings, taken directly from the email item:
Subject = The email item's subject line as it is stored in your email. OAR limits the length of the subject line in all items to 20 characters.
Sent by = The person who sent the original email item (with attachment).
Date sent = The date and time that the original email item (with attachment) was sent to you. The format for this field is mm-dd-yyyyhhmmss.
AttachmentExtension = All email text files are stored in .rtf file format for easy portability.
OAR removes what are known as illegal file name characters from the subject, sent by, and date sent fields. Illegal file name characters are characters that Windows does not permit in file names (such as the semi-colon/colon, quote marks, forward/backward slashes, etc.).
OAR names attachments using similar rules. Click here for details about how this is done!