The Article Buffer
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Select Methods
All commands for posting and mailing will put you in a message buffer where you can edit the article all you like, before you send the article by pressing C-c C-c. See Top. If you are in a foreign news group, and you wish to post the article using the foreign server, you can give a prefix to C-c C-c to make Gnus try to post using the foreign server.
Also see see Canceling and Superseding for information on how to remove articles you shouldn't have posted.