Emacs 24: Gnus: `smtpmail-auth-credentials' was removed

いつの間にか Emacs 24 がリリースされていたので、好奇心で使い始めた。Emacs 23 での設定をそのまま引き継いだが、問題なく動く。楽勝じゃん! て調子で仕事してたら、その日の終わりにメールが送れなくなってることに気が付いた。orz

具体的には、Gnus でメール送信時に「SMTP user name for <HOSTNAME>:」って聞かれる。何でこんな基本的なところが動かなくなるんだよ、と恨めしく思いながら調べると、これだ。

• Emacs NEWS 24.1

** SMTPmail

*** SMTPmail now uses encrypted connections (via STARTTLS) by default
if the mail server supports them.  This uses either built-in GnuTLS
support, or the starttls.el library.  Customize `smtpmail-stream-type'
to change this.

*** The variable `smtpmail-auth-credentials' has been removed.
By default, the information is now stored in the file ~/.authinfo.
This was the default value of smtpmail-auth-credentials.  If you had
customized smtpmail-auth-credentials to a list of user names and
passwords, those settings are not used.  During your first connection
to the smtp server, Emacs will prompt for the user name and password,
and offer to save them to ~/.authinfo.  Or you can manually copy the
credentials to ~/.authinfo.  For example, if you had

  (setq smtpmail-auth-credentials
        '(("mail.example.org" 25 "jim" "s!cret")))

then the equivalent line in ~/.authinfo would be

  machine mail.example.org port 25 login jim password s!cret

See the auth-source manual for more information, e.g. on encrypting
the credentials file.

*** The variable `smtpmail-starttls-credentials' has been removed.
If you had that set, you need to put

  machine smtp.whatever.foo port 25 key "~/.my_smtp_tls.key" cert "~/.my_smtp_tls.cert"

in your ~/.authinfo file instead.

smtpmail-{auth,starttls}-credentials は無くなったので代わりに ~/.authinfo を使え、と。しかもデフォルトで TLS にまで対応してくれちゃうらしい。TLS は使ってないので知らないが、~/.authinfo の方は作ったらサクッと動いた。

しかしこれ、みんな知ってるんかな? 検索しても目ぼしいものが出てこないけど。まあ、Gnus 使ってる人はこれくらい自己解決してるのが当たり前、ということなんだろう。