退信原因:发件人(youtubedubbing@mail.spring4all.com)域名的DNS记录未设置或设置错误导致对方拒收此邮件。 host gmail-smtp-in.l.google.com[142.251.10.26] said: 550-5.7.26 This mail is unauthenticated, which poses a security risk to the sender and Gmail users, and has been blocked. The sender must authenticate with at least one of SPF or DKIM. For this message, DKIM checks did not pass and SPF check for [mail.spring4all.com] did not pass with ip: [54.204.34.130]. The sender should visit https://support.google.com/mail/answer/81126#authentication for instructions on setting up authentication. k191-20020a636fc8000000b00565bcd33890si6279798pgc.848 - gsmtp (in reply to end of DATA command) 解决方案:请通知你的邮箱管理员为邮箱域名设置正确的DNS(SPF、DKIM、DMARC)记录。详细请见 http://service.exmail.qq.com/cgi-bin/help?subtype=1&&no=1000580&&id=20012 。
String name = "DD"; String host = "blog.didispace.com"; String result = new StringBuilder() .append("hello ") .append(name) .append(", your blog is ") .append(host) .toString();