mh-identity-list

mh-identity-list is a variable defined in `mh-e.el'.
Its value is

nil

Documentation:
*List of identities.

To customize this option, click on the "INS" button and enter a label
such as "Home" or "Work". Then click on the "INS" button with the
label "Add at least one item below". Then choose one of the items in
the "Value Menu".

You can specify an alternate "From:" header field using the "From
Field" menu item. You must include a valid email address. A standard
format is "First Last ". If you use an initial
with a period, then you must quote your name as in '"First I. Last"
'. People usually list the name of the company
where they work using the "Organization Field" menu item. Set any
arbitrary header field and value in the "Other Field" menu item.
Unless the header field is a standard one, precede the name of your
field's label with "X-", as in "X-Fruit-of-the-Day:". The value of
"Attribution Verb" overrides the setting of
`mh-extract-from-attribution-verb'. Set your signature with the
"Signature" menu item. You can specify the contents of
`mh-signature-file-name', a file, or a function. Specify a different
key to sign or encrypt messages with the "GPG Key ID" menu item.

You can select the identities you have added via the menu called
"Identity" in the MH-Letter buffer. You can also use
M-x mh-insert-identity. To clear the fields and signature added by the
identity, select the "None" identity.

The "Identity" menu contains two other items to save you from having
to set the identity on every message. The menu item "Set Default for
Session" can be used to set the default identity to the current
identity until you exit Emacs. The menu item "Save as Default" sets
the option `mh-identity-default' to the current identity setting. You
can also customize the `mh-identity-default' option in the usual
fashion.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 7.1 of the MH-E package that is part of Emacs 22.1.