diff -r 33006bd6a1d7 -r dffe78d80a6c mercurial/mail.py
--- a/mercurial/mail.py	Sun May 15 11:32:11 2016 -0700
+++ b/mercurial/mail.py	Sun May 15 11:38:38 2016 -0700
@@ -139,7 +139,7 @@
         s.ehlo()
     if (starttls or smtps) and verifycert:
         ui.note(_('(verifying remote certificate)\n'))
-        sslutil.validator(ui, mailhost)(s.sock, verifycert == 'strict')
+        sslutil.validatesocket(s.sock, verifycert == 'strict')
     username = ui.config('smtp', 'username')
     password = ui.config('smtp', 'password')
     if username and not password: