SMTP Status Codes and Error Messages from Error 512
SMTP status code – 512 – The host server for the recipient’s domain name cannot be found (DNS error)
(also called SMTP Error 5.1.2)
SMTP Error 512 : This SMTP reply code is received
when one of the servers on the way to the destination is
unable to resolve the domain name of a recipient email
address. Said differently : one of the servers on the way
to the destination, including your server or your ISP, has a
DNS problem or, possibly correctly, does not like one of
the email addresses in the message’s TO, CC, and BCC
The first check you should perform to resolve a 5.1.2 reply
code is to check all the recipient email addresses for
incorrect domain names (misspelt domain names, or,
maybe, totally non-existent domain names) – remember,
error code 512 is very specifically an error with the
domain name of one of the recipient email addresses.
You can call the recipient(s) or use the WHOIS tool of The
Ultimate Troubleshooter. If all the recipient email
addresses check out as regards the domain part of the
email addresses, then one of the servers on the way to the
recipient(s) has DNS problems – usually this will be one of
the first 2 servers in the chain, your own mail server (or
your network) or your ISP’s mail server.
Examples of typical SMTP error 512 messages : “5.1.2 –
Bad destination host ‘DNS Hard Error looking up domain”,
or “SMTP Error 550 5.1.2 Host unknown – host cannot be
found”, or how about this fantastically informative error
message “5.1.2 The message could not be delivered
because the recipient’s destination email system is
unknown or invalid. Please check the address and try
again, or contact your system administrator to verify
connectivity to the email system of the recipient.”.
In summary : most SMTP error 512 conditions are
caused by misspellings of the domain name part of a
recipient email address. However, with the proliferation
of spam, error 512 is also often encountered by automatic
“out-of-office” replies to junk mail because the domain
names used by junk mail are often bogus domain names.
Above are list of SMTP Errors Codes and Status Codes along with Error and Warning messages from Error 512 received while performing certain operation against mail server applications or related products.
What are SMTP Error Messages?
Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission. SMTP protocol is used for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP.
In general, each SMTP error contains the following information:
• The SMTP Status Code or SMTP Error Codes or SMTP Reply Codes
• The message text. This text is usually returned with the Error code. Some messages employ word substitution, where the word substituted represents the system-replacement of a term more specific to the occurrence.
• An explanation of how the error may have occurred.
Hope this was helpful.
Information about SMTP Error Codes or Status Codes and Error Messages on Windows, Linux Operating Systems.