mx record การใช้

• Nolisting is simply the adding of an MX record pointing to a non-existent server as the " primary " ( i . e . that with the lowest preference value )-which means that an initial mail contact will always fail.
• :: : Strictlier speaking, for mail purposes, the right side of an address really is a domain name, since it usually points to an MX record and is only interpreted as a host name if the MX record is absent.
• :: : Strictlier speaking, for mail purposes, the right side of an address really is a domain name, since it usually points to an MX record and is only interpreted as a host name if the MX record is absent.
• When delivering email, a mail server uses the domain name system ( DNS ) to look up the mail exchanger record ( MX record ) for the recipient's domain ( the part of the email address on the right of @ ).
• Re-attempting with more distant MX records makes a lot of sense if the primary MX's failure is considered non-authoritative; that is, if there is an expectation that the message may yet be delivered by the backup MX servers.
• The nolisting technique is simply the adding of an MX record pointing to a non-existent server as the " primary " ( i . e . that with the lowest preference value )  which means that an initial mail contact will always fail.
• One special case in RFC 1123 are gateways from or to other networks like UUCP and NetNews, where the first sending MTA cannot reach the final receiver directly with TCP . It is solved by MX records and if necessary rewriting foreign addresses at the gateway.
• Shorter TTLs can cause heavier loads on an authoritative nameserver, but can be useful when changing the address of critical services like Web servers or MX records, and therefore are often lowered by the DNS administrator prior to a service being moved, in order to minimize disruptions.
• The delay between when a domain's servers come online and when delayed messages are finally delivered can be anywhere from minutes to days, depending on the retry schedule of the sending servers . " This " is the problem that backup MX records are uniquely qualified to solve.
• However, the requirement to use a form is prohibited by several Internet RFCs, and the availability of abuse ( at ) example . com ( in this case abuse ( at ) yahoo . com ) is required by the Invariants clause of RFC 2142 because the domain has a mail server and MX record.