信箱不可用。服务器响应为：5.7.1无法中继错误 [英] Mailbox unavailable. The server response was: 5.7.1 Unable to relay Error
问题描述
我knw这个问题可能标志着重复，但我还没有找到解决我的问题，所以张贴我的问题。
我主持我netsol服务器上的网站之一。从那里contact.aspx具有使用Exchange Server来发送邮件。
I have Hosted one of my website on netsol server. From there a contact.aspx has to send mail using exchange server.
错误：邮箱不可用。服务器响应为：5.7.1无法中继
Error: Mailbox unavailable. The server response was: 5.7.1 Unable to relay
code：
MailMessage message = new MailMessage(@"xxx@xxx.com", @"test_user@yahoo.com", "New Message", "Exchange");
SmtpClient mail = new SmtpClient("exchange.abc.com", 29);
mail.EnableSsl = true;
mail.Credentials = new NetworkCredential(@"xxx@xxx.com", @"password");
mail.UseDefaultCredentials = false;
mail.DeliveryMethod = SmtpDeliveryMethod.Network;
mail.Send(message);
选项我尝试：
- 测试在端口465或587或25
- 改变SmtpDeliveryMethod.PickupDirectoryFromIis
- 无法配置IIS（SMTP服务器），因为它是其他的服务器上承载
那么，什么可能是这背后的问题？
So what could be problem behind this??
推荐答案
大多数SMTP服务器的默认配置是不是从不受信任的来源外域的中继。例如，假设您联系foo.com SMTP服务器，并要求它发送邮件到bar@xyzzy.com。因为SMTP服务器并不真正知道你是谁，它会拒绝中继消息。如果服务器的没有的为你做的，这将被视为一个开放中继，这是垃圾邮件发送者如何经常做自己的事情。
The default configuration of most SMTP servers is not to relay from an untrusted source to outside domains. For example, imagine that you contact the SMTP server for foo.com and ask it to send a message to bar@xyzzy.com. Because the SMTP server doesn't really know who you are, it will refuse to relay the message. If the server did do that for you, it would be considered an open relay, which is how spammers often do their thing.
如果您联系foo.com邮件服务器，并要求其将邮件发送到somebody@foo.com，它的可能的让你做到这一点。如果他们信任你是你说你是谁这要看。通常情况下，服务器将尝试做一个反向DNS查找，并拒绝发送邮件，如果你发送的IP不匹配DNS MX记录的IP地址。所以，如果你说你是bar.com邮件服务器，但你的IP地址不匹配bar.com MX记录，那么它会拒绝传递邮件。
If you contact the foo.com mail server and ask it to send mail to somebody@foo.com, it might let you do it. It depends on if they trust that you're who you say you are. Often, the server will try to do a reverse DNS lookup, and refuse to send mail if the IP you're sending from doesn't match the IP address of the MX record in DNS. So if you say that you're the bar.com mail server but your IP address doesn't match the MX record for bar.com, then it will refuse to deliver the message.
您需要倾诉的SMTP服务器来获取认证信息的管理员，以便它将使继电器为您服务。你需要present这些凭据当您联系SMTP服务器。通常它要么用户名/口令，或它可以使用Windows权限。取决于服务器和它的配置方式。
You'll need to talk to the administrator of that SMTP server to get the authentication information so that it will allow relay for you. You'll need to present those credentials when you contact the SMTP server. Usually it's either a user name/password, or it can use Windows permissions. Depends on the server and how it's configured.
请参阅无法发送使用SMTP 对于如何发送凭证为例邮件到外部域。
See Unable to send emails to external domain using SMTP for an example of how to send the credentials.
这篇关于信箱不可用。服务器响应为：5.7.1无法中继错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
