### 4.10 Other Commands

This section documents a handful of commands and variables that don’t fit into any of the other documentation categories.

`q`

  Quit out of IMAIL (`imail-quit`). This closes all open IMAP connections and buries all IMAIL buffers. With prefix argument, only affects the current IMAIL buffer, leaving any other IMAIL buffers alone.

`M-d`

  Disconnect from the IMAP server (`imail-disconnect`).

`b`

  Bury the IMAIL buffer (`imail-bury`).

`s`

  Save changes in the current folder to disk (`imail-save-folder`).

When you are finished reading mail in a folder, use the `q` command (`imail-quit`). This command closes the folder, then buries the buffer. Closing a folder has different effects, depending on the type of folder. Closing an IMAP folder causes IMAIL to disconnect from the IMAP server (go offline). Closing a file folder saves any changes out to the corresponding file. In both cases, internal data structures may be dropped, requiring them to be rebuilt, should the folder later be re-opened. In no case are any changes made to the folder’s contents; in particular, deleted messages are not expunged.

On IMAP folders, the `q` command is equivalent to `M-d b`. On file folders, the `q` command is equivalent to `s b`.

The `M-d` command (`imail-disconnect`) disconnects IMAIL from the IMAP server (goes offline). This has no effect on file folders.

The `b` command (`imail-bury`) buries the selected IMAIL buffer. Burying a buffer means moving it to the bottom of the buffer list and selecting another buffer from the top of the list. This is similar to the command `bury-buffer`, except that any summary buffer associated with this buffer is also buried, and if a window was created to hold the summary buffer, it is deleted.

The `s` command (`imail-save-folder`) saves out any changes to the selected IMAIL folder. For file folders, this means writing the folder back out to its file. For IMAP folders, this no effect. In no case are any changes made to the folder’s contents; in particular, deleted messages are not expunged.

IMAIL normally caches IMAP message bodies in memory in order to increase performance. The variable `imail-body-cache-limit` gives you some control over how this caching is done. `imail-body-cache-limit` is normally set to a positive integer, meaning that any message body or in-line MIME entity whose size in bytes is less than this number is cached. However, caching can be entirely disabled by setting `imail-body-cache-limit` to `#f`, or made unconditional by setting it to `#t`.

Another thing that IMAIL caches is IMAP passwords. This is done so that you don’t have to keep typing your password whenever you connect to a new IMAP folder. However, this is also a security risk, because the password is kept in Scheme’s memory. The variable `imail-pass-phrase-retention-time` says how long passwords are cached, in minutes. Normally this is set to 30 minutes, but if you are paranoid you can set it to zero to disable password caching altogether. Scheme keeps track of the use of each password, and deletes its copy of the password when it has expired. Additionally, Scheme stores passwords in an obscured form, to prevent them being seen during casual browsing through memory structures, but this does not provide any protection against a deliberate attempt to find the password.