Mutt: select multiple messages

You need to run the tag-pattern command. The default for that is T (Shift+t). You can then give it a regular expression. By default this will match message subjects.

If you need to select a range of messages by number, you can provide the ~m [MIN]-[MAX] pattern to tag-pattern. There are many other options I've found useful over the years, and you can see a complete list in the “Advanced Usage - Patterns” section of the manual.

You can also use t to tag or untag the highlighted message, to fine-tune the selection.

Then you can run tag-prefix (;) followed by save-message (s), and it will prompt you for a mailbox name. This command marks the saved messages to be deleted; there is also the copy-message command (C, i.e. Shift+c) to copy without marking for deletion.

Extending @Scott McClung's correct answer:

If you want to apply mutt commands by default to all selected (tagged) messages without using tag-prefix (bound to ; by default), you can set the auto_tag variable by adding this line to your .muttrc:

set auto_tag = yes

Check also http://www.sendmail.org/~ca/email/mutt/manual-4.html + http://www.rosipov.com/blog/effective-search-with-mutt/ for useful flags like ~d 31/12/99-01/01/00 ~s Y2K ~b scared.

L uses the same syntax to browse only a subset of your inbox, eg ~f [email protected] ~B your father.