Is there some kind of address-book, so I needn’t remember all those email addresses?
There’s a very basic solution for this, mail aliases. You can store your mail addresses in a ~/.mailrc file using a simple alias syntax:
alias al "Al <al@english-heritage.invalid>"
Then typing your alias (followed by a space or punctuation character) on a To: or Cc: line in the message buffer will cause Gnus to insert the full address for you. See the node "Mail Aliases" in Message (not Gnus) manual for details.
However, what you really want is the Insidious Big Brother Database bbdb. Get it from bbdb’s website. Now place the following in ~/.gnus.el, to activate bbdb for Gnus:
(require 'bbdb) (bbdb-initialize 'gnus 'message)
Now you probably want some general bbdb configuration, place them in ~/.emacs:
(require 'bbdb)
;;If you don't live in Northern America, you should disable the
;;syntax check for telephone numbers by saying
(setq bbdb-north-american-phone-numbers-p nil)
;;Tell bbdb about your email address:
(setq bbdb-user-mail-names
(regexp-opt '("Your.Email@here.invalid"
"Your.other@mail.there.invalid")))
;;cycling while completing email addresses
(setq bbdb-complete-name-allow-cycling t)
;;No popup-buffers
(setq bbdb-use-pop-up nil)
Now you should be ready to go. Say M-x bbdb RET RET to open a bbdb buffer showing all entries. Say c to create a new entry, b to search your BBDB and C-o to add a new field to an entry. If you want to add a sender to the BBDB you can also just hit : on the posting in the summary buffer and you are done. When you now compose a new mail, hit TAB to cycle through know recipients.