M takes you back to the Mail Menu. Q is used for quitting the Pine mail system. C is to compose a letter. This takes you to the compose screen. G lets you select a folder to go to.
T is for storing email addresses.
S will save your document to a different file. E will let you export a message to your home computer files. X will expunge or get ride of all email you deleted before you log off the Pine system. This is handy if you have a lot of email. H enables full headers.