这个错误时有发生，我找不到这个问题的根源。请帮我解决这个问题。
1 个解决方案
#1
2
SMTP Status Codes
4.2.1
4.2.1
The Mail transfer service is unavailable because of a transient event. SMTP reply
由于临时事件，邮件传输服务不可用。SMTP回复
421 can be caused by many things but generally indicates that the mail server which returns this status code is currently unavailable but may be available later.
421可以由许多事情引起，但通常表示返回此状态代码的邮件服务器目前不可用，但稍后可能会提供。
For example, the server administrator may have stopped the mail service to troubleshoot a problem, or the mail server is right in the middle of rebooting, or the mail server is currently processing too many incoming messages or incoming requests, etc... Note : “Mail Server” in this case can be any of the mail servers on the message’s route – the sending server (your server), the ISP SMTP server, or the recipient’s mail server.
例如，服务器管理员可能已经停止了邮件服务来解决问题，或者邮件服务器正处于重启的过程中，或者邮件服务器目前正在处理过多的传入消息或传入请求，等等……注意:在本例中，“邮件服务器”可以是消息路由上的任何邮件服务器——发送服务器(您的服务器)、ISP SMTP服务器，或收件人的邮件服务器。
Clearly, if you repeatedly receive an SMTP status 421 then the problem is no longer of a transient nature and you need to investigate or inform the relevant network administrator, ISP tech support, or the recipient.
显然，如果您重复接收SMTP状态421，那么问题就不再是瞬态特性，您需要调查或通知相关的网络管理员、ISP技术支持或接收方。
SMTP Response 421 can also be received as a result of your message server sending an email where the total number of TO, CC, and BCC users results in a number of simultaneous SMTP connections that is in excess of the number of connections your ISP or SMTP service allows. A typical error message for this situation would be : “421 Too many concurrent SMTP connections from this IP address; please try again later”. Typically, when this happens your server will have sent some of the messages (note that for all servers, each email sent by a user always gets broken down into individual separate emails to each of the recipients in the TO, CC, and BC fields), and will automatically retry a little later to send the remaining messages.
SMTP响应421也可以接收到您的消息服务器发送电子邮件的结果，其中的总数量为，CC和BCC用户导致了许多并发的SMTP连接，这超过了您的ISP或SMTP服务允许的连接数量。这种情况的典型错误消息是:“来自这个IP地址的并发SMTP连接太多了;请稍后再试”。通常,当这一切发生的时候你的服务器会发送一些信息(注意,对于所有服务器,每个用户发送的邮件总是分为个人单独的每个收件人的邮件,抄送,公元前和字段),和稍后会自动重试发送剩余的消息。
Source http://wiki.mattrude.com/SMTP_Status_Codes
源http://wiki.mattrude.com/SMTP_Status_Codes
#1
2
SMTP Status Codes
4.2.1
4.2.1
The Mail transfer service is unavailable because of a transient event. SMTP reply
由于临时事件，邮件传输服务不可用。SMTP回复
421 can be caused by many things but generally indicates that the mail server which returns this status code is currently unavailable but may be available later.
421可以由许多事情引起，但通常表示返回此状态代码的邮件服务器目前不可用，但稍后可能会提供。
For example, the server administrator may have stopped the mail service to troubleshoot a problem, or the mail server is right in the middle of rebooting, or the mail server is currently processing too many incoming messages or incoming requests, etc... Note : “Mail Server” in this case can be any of the mail servers on the message’s route – the sending server (your server), the ISP SMTP server, or the recipient’s mail server.
例如，服务器管理员可能已经停止了邮件服务来解决问题，或者邮件服务器正处于重启的过程中，或者邮件服务器目前正在处理过多的传入消息或传入请求，等等……注意:在本例中，“邮件服务器”可以是消息路由上的任何邮件服务器——发送服务器(您的服务器)、ISP SMTP服务器，或收件人的邮件服务器。
Clearly, if you repeatedly receive an SMTP status 421 then the problem is no longer of a transient nature and you need to investigate or inform the relevant network administrator, ISP tech support, or the recipient.
显然，如果您重复接收SMTP状态421，那么问题就不再是瞬态特性，您需要调查或通知相关的网络管理员、ISP技术支持或接收方。
SMTP Response 421 can also be received as a result of your message server sending an email where the total number of TO, CC, and BCC users results in a number of simultaneous SMTP connections that is in excess of the number of connections your ISP or SMTP service allows. A typical error message for this situation would be : “421 Too many concurrent SMTP connections from this IP address; please try again later”. Typically, when this happens your server will have sent some of the messages (note that for all servers, each email sent by a user always gets broken down into individual separate emails to each of the recipients in the TO, CC, and BC fields), and will automatically retry a little later to send the remaining messages.
SMTP响应421也可以接收到您的消息服务器发送电子邮件的结果，其中的总数量为，CC和BCC用户导致了许多并发的SMTP连接，这超过了您的ISP或SMTP服务允许的连接数量。这种情况的典型错误消息是:“来自这个IP地址的并发SMTP连接太多了;请稍后再试”。通常,当这一切发生的时候你的服务器会发送一些信息(注意,对于所有服务器,每个用户发送的邮件总是分为个人单独的每个收件人的邮件,抄送,公元前和字段),和稍后会自动重试发送剩余的消息。
Source http://wiki.mattrude.com/SMTP_Status_Codes
源http://wiki.mattrude.com/SMTP_Status_Codes