Knowledge Base

Is it default behavior of Plesk that mail is getting deferred in case of DNS lookup failure?

Question

Is it default behavior of Plesk that mail is getting deferred in case of DNS lookup failure with the following message?

「451 4.7.24 SPF validation defer.」

Answer

This is default behavior in case SPF checking mode is set as Reject mail when SPF resolves to "fail" (deny) at Tools & Settings > Mail Server Settings > SPF spam protection page.

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DNS_PROBE_FINISHED_NXDOMAIN: What Is It And How To Fix The Problem

Knowledge Base

Email header analysis reports SPF failed for localhost IP on mail sent from Plesk hosted mailbox: SPF Authentication : SPF Failed for IP – 127.0.0.1

Cannot receive or send mail on a Plesk server

Websites on Plesk server are slow or show error 500 or PHP mail cannot be sent: ap_pass_brigade failed

Mail delivery does not work: do not list domain in BOTH mydestination and virtual_mailbox_domains

Hosting Wiki

Knowledge Base

Is it default behavior of Plesk that mail is getting deferred in case of DNS lookup failure?

Question

Answer

Securing the WordPress Frontier with WP Guardian

Introducing WP Guardian Vulnerability Protection: Now available for WP Toolkit

DNS_PROBE_FINISHED_NXDOMAIN: What Is It And How To Fix The Problem

Email header analysis reports SPF failed for localhost IP on mail sent from Plesk hosted mailbox: SPF Authentication : SPF Failed for IP – 127.0.0.1

Cannot receive or send mail on a Plesk server

Websites on Plesk server are slow or show error 500 or PHP mail cannot be sent: ap_pass_brigade failed

Mail delivery does not work: do not list domain in BOTH mydestination and virtual_mailbox_domains

Install Is it default behavior of Plesk that mail is getting deferred in case of DNS lookup failure? extension