Mail and news

• How do I change the included text prefix in mail/news followups?
• How do I save a copy of outgoing mail?
• Why doesn’t Emacs expand my aliases when sending mail?
• How can I sort the messages in my Rmail folder?
• Why does Rmail need to write to /var/spool/mail?
• How can I force Rmail to reply to the sender of a message, but not the other recipients?
• How do I make Emacs automatically start my mail/news reader?
• How do I read news under Emacs?
• How do I make Gnus faster?
• How do I catch up all newsgroups in Gnus?