De docs
oficiais do muttThese address groups can also be created implicitly by the alias, lists, subscribe and alternates commands by specifying the optional -group option. For example,
alternates -group me address1 address2 alternates -group me -group work address3
would create a group named “me” which contains all your addresses and a group named “work” which contains only your work address address3. Besides many other possibilities, this could be used to automatically mark your own messages in a mailing list folder as read or use a special signature for work-related messages.
Recomendo que você leia o restante do documento para ver o que mais você pode fazer com todas as opções disponíveis
espero que ajude