家サーバをリブートしたらどっさりメールが届いたのは、どうも、postfixが何かの拍子にリスタートされたあとに
status=deferred (Host or domain name not found. Name service error for name=smtp.gmail.com type=AAAA: Host not found, try again)
になるからみたい。いくつか警告が出てるのが関連してるのかしら。
postfix[973]: Postfix is running with backwards-compatible default settings
postfix[973]: See http://www.postfix.org/COMPATIBILITY_README.html for details
postfix[973]: To disable backwards compatibility use "postconf compatibility_level=2" and "postfix reload"
postfix/postfix-script[1153]: warning: symlink leaves directory: /etc/postfix/./makedefs.out
postfix/postfix-script[1209]: warning: /var/spool/postfix/etc/ssl/certs/ca-certificates.crt and /etc/ssl/certs/ca-certificates.crt differ
postfix/postfix-script[1215]: warning: /var/spool/postfix/etc/resolv.conf and /etc/resolv.conf differ
postfix/postfix-script[1236]: starting the Postfix mail system
postfix/master[1238]: daemon started -- version 3.4.13, configuration /etc/postfix