You're probably better off using Applescript or something similar that allows you more control over manipulating the properties of the individual messages.
EDIT: Took a lot more trial and error than i thought it would, but you should be able to select a batch of messages, run this script, and have it spit out folders for each sender in whatever folder you specify at the outset. It doesn't do logging, but perhaps its enough to get you started.
I'll also note that the save [attachment] in [attachmentPath] command is broke in Lion on 10.7 and 10.7.1 (I think its both), but appears to be fixed in 10.7.2, based on what I've been reading. So YMMV if you're not running 10.7.2.
EDIT Again: More Revisions... now we won't create folders for messages that don't have attachments...
tell application "Mail"
set selectedMessages to selection
set destinationFolder to choose folder with prompt "Pick a Destination"
repeat with currentMessage in selectedMessages
repeat 1 times
set msgSender to sender of currentMessage
set msgAttachments to mail attachments of currentMessage
if (msgAttachments is equal to {}) then
exit repeat
end if
tell application "Finder"
if not (exists folder msgSender of destinationFolder) then
set senderFolder to (make new folder at destinationFolder with properties {name:msgSender})
else
set senderFolder to (folder msgSender of destinationFolder)
end if
end tell
repeat with currentAttachment in msgAttachments
if (downloaded of currentAttachment is true) then
set currentAttachmentPath to (senderFolder as string) & (name of currentAttachment)
save currentAttachment in currentAttachmentPath
end if
end repeat
end repeat
end repeat
end tell