Enigmail has a lot of configurable settings and options. The default values
are suitable for most users. If you want to know more about the options and
their meaning, this section provides you with the answer.
All settings are available through the menu OpenPGP > Preferences
Files and Directories: Contains the path to the GnuPG executable (gpg). If the information line above the entry field says that GnuPG was found, then the field can be left empty. The path can also be specified relative to the installation directory of Thunderbird/SeaMonkey. In order to specify a value, you first have to tick the "Override with" box.
Typical path settings: on Windows: C:\Program Files\GnuPG\gpg.exe
on Linux: /usr/bin/gpg
relative to Thunderbird: ..\GnuPG\gpg.exe
Remember password for ... minutes idle time: Determine for how long your GnuPG password should be kept in memory if you don't use Mozilla. This is a certain security trade-off if other people might have access to your computer while you are absent. To disable the password caching, set the value to 0.
Never ask for any passphrase: If you have no passphrase for your key, enable this option to prevent Enigmail from asking you your passphrase and passing it to GnuPG.
Note: The passphrase is implemented in a safe way concerning accessibility from other users or programs or unsigned scripts/web sites etc, but if the email application is swapped to disk, then the passphrase also is swapped to disk. You should not use passphrase caching if you want to be sure that this does not happen.
Display expert settings: Enable this checkbox to see more tabs and menus with options and features targeted for advanced users.
Next: Per Account Settings