A system for processing e-mail messages receives, from an e-mail
repository, a transactional e-mail message comprising message attribute
data. The system places the transactional e-mail message in an e-mail
thread in response to the message attribute data of the transaction
e-mail message. The system determines whether one or more derived e-mail
messages are included in the transactional e-mail message. If one or more
derived e-mail messages are included, the system determines derived
message attribute data of the one or more derived e-mail messages. The
system then places the derived e-mail message in the e-mail thread in
response to the derived message attribute data of the derived e-mail
message.