smtp: verify the certificate of the SMTP server for STARTTLS/SMTPS Before this patch, the certificate of the SMTP server for STARTTLS or SMTPS isn't verified. This may cause man-in-the-middle security problem (stealing authentication information), even though SMTP channel itself is encrypted by SSL. When "[smtp] tls" is configured as "smtps" or "starttls", this patch: - uses classes introduced by preceding patches instead of "SMTP" or "SMTP_SSL" of smtplib, and - verifies the certificate of the SMTP server, if "[smtp] verifycert" is configured as other than False "[smtp] verifycert" can be configured in 3 levels: - "strict": This verifies peer certificate, and aborts if: - peer certification is not valid, or - no configuration in "[hostfingerprints]" and "[web] cacerts" This is default value of "[smtp] verifycert" for security. - "loose": This verifies peer certificate, and aborts if peer certification is not valid. This just shows warning message ("certificate not verified"), if there is no configuration in "[hostfingerprints]" and "[web] cacerts". This is as same as verification for HTTPS connection. - False(no verification): Peer certificate is not verified. This is as same as the behavior before this patch series. "hg email --insecure" uses "loose" level, and ignores "[web] cacerts" as same as push/pull/etc... with --insecure. Ignoring "[web] cacerts" configuration for "hg email --insecure" is already done in "dispatch._dispatch()" by looking "insecure" up in the table of command options.

--- a/mercurial/help/config.txt	Tue Mar 26 02:28:10 2013 +0900
+++ b/mercurial/help/config.txt	Tue Mar 26 02:28:10 2013 +0900
@@ -1052,6 +1052,16 @@
     Optional. Method to enable TLS when connecting to mail server: starttls,
     smtps or none. Default: none.
 
+``verifycert``
+    Optional. Verification for the certificate of mail server, when
+    ``tls`` is starttls or smtps. "strict", "loose" or False. For
+    "strict" or "loose", the certificate is verified as same as the
+    verification for HTTPS connections (see ``[hostfingerprints]`` and
+    ``[web] cacerts`` also). For "strict", sending email is also
+    aborted, if there is no configuration for mail server in
+    ``[hostfingerprints]`` and ``[web] cacerts``.  --insecure for
+    :hg:`email` overwrites this as "loose". Default: "strict".
+
 ``username``
     Optional. User name for authenticating with the SMTP server.
     Default: none.