rmail-summary-by-topic
rmail-summary-by-topic is an interactive autoloaded Lisp function in `rmailsum.el
'.
(rmail-summary-by-topic SUBJECT &optional WHOLE-MESSAGE)
Display a summary of all messages with the given SUBJECT.
Normally checks just the Subject field of headers; but with prefix
argument WHOLE-MESSAGE is non-nil, looks in the whole message.
SUBJECT is a string of regexps separated by commas.