我有我的 Mandrill 帐户向许多客户发送电子邮件。使用 xxx@nauta.cu 类型地址的人根本没有收到任何电子邮件，当我去 Mandrill 时，它说：
2015 年 11 月 8 日晚上 11:39 450 4.1.8 ：发件人地址被拒绝：找不到域 发件人：198.2.178.1 发件人：181.225.231.50
当我从我的 gmail 向该 nauta.cu 帐户发送电子邮件时，它可以工作。此外，如果我从 Mandrill 向我的 gmail 帐户发送电子邮件，它也可以工作。
这是 nata.cu 的 nslookup 的结果
nslookup nauta.cu 服务器：127.0.1.1 地址：127.0.1.1#53
非权威答案：*** 找不到 nauta.cu：无答案
这对我的公司来说非常重要且时间紧迫。我已经挣扎了好几天，我真的很感激任何能引导我走上正确道路的线索。
您必须按照此处的说明设置发送域：https ://mandrill.zendesk.com/hc/en-us/articles/205582387-How-to-Set-up-Sending-Domains 。有关该主题的更多背景讨论在这里：http ://blog.mandrill.com/we-are-making-domain-verification-mandatory.html 。
对于时间敏感的问题，我建议联系 Mandrill 支持。他们的反应非常迅速。要获得 Mandrill 支持，您只需登录 mandrillapp.com 并单击页面左下角的支持按钮。
希望这可以帮助，
The MX records for nauta.cu currently resolve to mail2.etecsa.net and mail3.etecsa.net, but the IP address that Mandrill tried to resolve in your example was 181.225.231.50. That IP was tied to mx2.etecsa.net, but is no longer in use by nuata.cu. So when Mandrill first tried to deliver your email to nauta.cu, it was likely during the time when the old MX record (181.225.231.50) was still cached, and before the new ones had fully propagated.
This is probably resolved now since the TTL on nauta.cu's MX records is so low, but Mandrill's servers are likely retrying delivery for some time until the emails ultimately bounce, and then they'll stop trying to send those same emails. For example, when a receiving SMTP server (nauta.cu's in this case) returns a 4xx type of error, most sending servers (like Mandrill's) will retry delivery for a set period of time before giving up. You'll probably end up having to manually re-send these emails if you want them to get through, instead of waiting for Mandrill to bounce them.