Apple Mail and MailTags can do this. MailTags provides keyword tagging and adding of notes to mails. Notes can be set as subject. Full text search / Spotlight will find text in notes, too.
See http://www.indev.ca/MailTags.html -- it is not possible to modify email subject https://bugs.launchpad.net/bugs/490935 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
