Each mail message has a header that consists of a list of
Name: Value lines. It is from these lines that
information such as the subject, the recipients, the sender, or the
date of the message are extracted. The
table contains the decoded header for each message. The lines are
unfolded, so the newline character can be seen as an effective
separator between successive entries. The lines are also decoded so
that they no longer contain quoted-printable or base64 contents, and
they're converted to the database character set (UTF-8).
Structure of header
Unique internal identifier of the message.
text The decoded contents of the entire header of the message. Lines are separated by newline characters (ASCII code=10).