mail error 550

"550 5.7.1 unable to relay for XXX" error in lumisoft Mail Server This error occurs when I explore lumisoft Mail ServerSource codeIn the process, it severely plagued me for a week. Fortunately, I am still very resilient to find the cause and

 Table (1) SMTP CodeCode definition421 service not available, hosts in the closing transmission channel brackets cannot provide normal services, close the transmission pipeline, and emails will be stuck on the host450 requested mail action not taken:

Original issue background:A few days ago, ops colleagues suddenly found that Zabbix monitoring no longer send mail, and Zabbix monitoring interface status can be displayed. Because there have been similar problems, estimated to be 163 mailbox

From: Author: (2001-11-2307: 08: 00) 1. the goal of the Simple Mail Transfer Protocol (SMTP) is to deliver mail reliably and efficiently. it is independent of the transfer subsystem and requires only one channel that can ensure the order of

From: Author: (2001-11-2307: 08: 00) 1. the goal of the Simple Mail Transfer Protocol (SMTP) is to deliver mail reliably and efficiently. it is independent of the transfer subsystem and requires only one channel that can ensure the order of

List of common error reports for Linux email servers-Linux Enterprise applications-Linux server application information. For details, refer to the following section. Server 400 Error Report Q: 421 Server too busy A: Unable to connect because the

3. 7. the domain was recently introduced to the ARPAInternet email system. The domain can be used to change the address space from a flat string host name to a global address level. A host is replaced by a domain name. The starting host is composed

When it comes to sending mail, first mention SMTP (hehe, the master will skip this section!). )。 The full name of SMTP is "Simple Mail Transfer Protocol", which is simply the message Transfer Protocol. It is a set of specifications for transferring

. NET, the function of sending mail has been encapsulated into the System.Web.Mail namespace of the. NET Framework, and using this namespace, it is easy to build a mail-sending program that requires only a good structure of the SMTP server in

1. Introduction The goal of Simple Mail Transfer Protocol (SMTP) is to transmit mail reliably and efficiently, which is independent of the transfer protocol.The delivery subsystem only requires a channel that can ensure the sequence of transmitted