These are all the variables you can set in MM. For more information on any variable, type help set followed by the name of the variable. Since the names are long, use the TAB key to fill them in; for example, type help set al and then TAB to get help about the variable aliases-use-groups.
Some variables interact with each other. Check the cross-references in the help screens to determine what may be affected when a variable is changed.
The command show shows the current value of variables, set changes the value, and save-init saves the current values permanently. See the help screen for each of those commands.
| aliases-use-groups | whether to show mail-aliases or expansions in sent mail |
| append-new-mail | whether to append to mbox or rewrite mbox |
| append-signature | whether to use a .signature file |
| auto-create-files | whether MM should create new files |
| auto-startup-get | whether to get the mail file at startup |
| autowrap-column | where to wrap lines in text mode |
| browse-clear-screen | whether to clear screens during browse |
| browse-pause | whether to pause during browse |
| check-interval | how often to check for new mail |
| clear-screen | whether to clear screen for each message being read |
| continuous-check | whether to check for new mail in all modes |
| control-d-automatic-send | whether to send automatically |
| control-e-editor | whether control-e calls the editor |
| control-l-confirm | whether control-l executes a command |
| control-n-abort | whether control-n aborts sending |
| crt-filter | which screen pager to use |
| default-bcc-list | bcc address for all outgoing mail |
| default-cc-list | cc address for all outgoing mail |
| default-fcc-list | fcc address for all outgoing mail |
| default-from | from field for all outgoing mail |
| default-mail-type | file format for new mail files |
| default-read-command | an automatic command in Read Mode |
| default-reply-to | reply-to field for all outgoing mail |
| default-send-command | an automatic command in Send Mode |
| directory-folders | whether to add a slash to directory names, for mh format |
| display-flagged-messages | whether to show flagged messages at startup |
| display-outgoing-message | whether to show message text on entering text mode |
| dont-print-headers | which header fields to hide (list, print) |
| dont-type-headers | which header fields to hide (read, type) |
| editor | what editor to use |
| escape-automatic-send | whether to send automatically |
| expunge-on-bye | whether the bye command expunges |
| fast-init-file | whether to write .mmfast |
| finger-command | define what the MM finger command does |
| gnuemacs-mmail | whether editor is gnuemacs with mmail support |
| handle-changed-modtime | how MM handles a certain file problem |
| header-options-file | define a file of extra header fields |
| help-dir | where the help files are |
| incoming-mail | where incoming mail is kept |
| keywords | define CCMD completions for keyword |
| list-include-headers | whether the list command includes headers |
| list-on-separate-pages | whether to have page breaks between messages |
| mail-aliases | define a mail alias (same as define command) |
| mail-directory | where mail files should be kept |
| mail-file | define the main mail file |
| mmail-path | define the gnuemacs library for MM |
| modify-read-only | whether read-only files can be modified |
| movemail-path | where the movemail program is |
| new-file-mode | file mode (permissions) for new files |
| only-print-headers | which header fields to show (list, print) |
| only-type-headers | which header fields to show (read, type) |
| personal-name | your name, for the from field |
| print-filter | define what program the MM print command uses |
| prompt-for-bcc | whether to prompt for bcc |
| prompt-for-cc | whether to prompt for cc |
| prompt-for-fcc | whether to prompt for fcc |
| prompt-rcpt-always | whether to always prompt for addresses |
| read-prompt | the prompt for Read Mode |
| reply-all | whether to use the option all for all replies |
| reply-include-me | whether the all option includes the sender |
| reply-indent | what mark to use for inclusions in replies |
| reply-initial-display | whether the reply command displays the outgoing message |
| reply-insert | whether to use the option including for all replies |
| saved-messages-file | define a file for copies of all outgoing mail |
| send-prompt | the prompt for Send Mode |
| send-verbose | whether to show where the mail is being sent |
| sendmail-background | whether to run sendmail in the background |
| sendmail-verbose | whether to show sendmail messages |
| speller | define what program the MM spell command uses |
| suspend-on-exit | whether the exit command suspends |
| suspend-on-quit | whether the quit command suspends |
| temp-directory | where to create temporary files |
| terse-text-prompt | whether to show the long Message prompt |
| top-level-prompt | the prompt for Top Level |
| use-crt-filter-always | whether to use the crt-filter always |
| use-editor-always | whether to use the editor all the time |
| use-invalid-address | whether to use strange addresses |
| user-headers | define CCMD completions for the user-header command |
| user-level | whether the hint line appears |
| user-name | your user name for MM |