help = 'send a patch or series of patches by e-mail'
-usage = """%prog [options] [<patch>]"""
+usage = """%prog [options] [<patch>]
+
+Send a patch or a range of patches (defaulting to the applied patches)
+by e-mail using the 'smtpserver' configuration option. The From/To/Cc
+addresses and the e-mail format are generated from the template file
+passed as argument to '--template' (defaulting to
+.git/patchmail.tmpl). A preamble e-mail can also be sent using the
+'--first' option (no default template).
+
+All the subsequent e-mails appear as replies to the first e-mail sent
+(either the preamble or the first patch). E-mails can be seen as
+replies to a different e-mail by using the '--refid' option.
+
+SMTP authentication is also possible with '--smtp-user' and
+'--smtp-password' options, also available as configuration settings:
+'smtpuser' and 'smtppassword'.
+
+The template e-mail headers and body must be separated by
+'%(endofheaders)s' variable, which is replaced by StGIT with
+additional headers and a blank line. The patch e-mail template accepts
+the following variables:
+
+ %(patch)s - patch name
+ %(shortdescr)s - the first line of the patch description
+ %(longdescr)s - the rest of the patch description, after the first line
+ %(endofheaders)s - delimiter between e-mail headers and body
+ %(diff)s - unified diff of the patch
+ %(diffstat)s - diff statistics
+ %(date)s - current date/time
+ %(patchnr)s - patch number
+ %(totalnr)s - total number of patches to be sent
+ %(authname)s - author's name
+ %(authemail)s - author's email
+ %(authdate)s - patch creation date
+ %(commname)s - committer's name
+ %(commemail)s - committer's e-mail
+
+For the preamble e-mail template, only the %(date)s, %(endofheaders)s
+and %(totalnr)s variables are supported."""
options = [make_option('-a', '--all',
help = 'e-mail all the applied patches',