delete<message list> delete messages
undelete<message list> undelete messages
save<message list> folder append messages to folder and mark as saved
copy<message list> folder append messages to folder without marking them
write<message list> file append message texts to file, save attachments
preserve<message list> keep incoming messages in mailbox even if saved
Reply <message list> reply to message senders
reply<message list> reply to message senders and all recipients
mail addresses mail to specific recipients
file folder change to another folder
quit quit and apply changes to folder
xit quit and discard changes made to folder
! shell escape
cd<directory> chdir to directory or home if none given
list list names of all available commands
这些交互命令是可以简化输入的linux命令，比如"headers"命令linux命令，就可以直接输入"h",这是列出邮件标题列表的命令。我们解释一下常用的交互命令。
