Set default when asking for send-mail-function (Bug#25874).

* lisp/mail/sendmail.el (sendmail-query-user-about-smtp): Pass first
option as default for `completing-read'.

1 files changed, 3 insertions, 2 deletions

diff --git a/lisp/mail/sendmail.el b/lisp/mail/sendmail.el
index 70c8ea1f937..42b688fbabc 100644
--- a/lisp/mail/sendmail.el
+++ b/lisp/mail/sendmail.el
@@ -555,8 +555,9 @@ This also saves the value of `send-mail-function' via Customize."
             (goto-char (point-min))
             (display-buffer (current-buffer))
             (let ((completion-ignore-case t))
-              (completing-read "Send mail via: "
-                               options nil 'require-match)))))
+              (completing-read
+               (format "Send mail via (default %s): " (caar options))
+               options nil 'require-match nil nil (car options))))))
     (customize-save-variable 'send-mail-function
                              (cdr (assoc-string choice options t)))))