SPF spam protection in Plesk
Plesk Obsidian 18.0.25 CentOS Linux 7.7
I get a lot of spam mail. What should I do?
SPF spam protection to prevent unwanted e-mail. This is a good idea, but it may prevent you from receiving the mail you want to receive.
There are many options for settings, and which one is best for you?
The following is a summary of the research I did.
SPF spam protection settings
Tools and Settings > Mail Server Settings > SPF Spam Protection
It is as described here.
https://docs.plesk.com/ja-JP/obsidian/administrator-guide/59433/
Continue SPF check if there is a problem with DNS lookup
"Continue SPF check if DNS lookup has problems".
Check ON if you want to receive all incoming messages regardless of the result of the SPF check, even if the SPF check fails due to a problem in DNS lookup.
SPF check mode
Only create Received SPF header. No blocking.
Accepts all incoming messages, regardless of the SPF check result.
Use temporary error notification when DNS lookup problems occur.
Accept all incoming messages regardless of the result of the SPF check, even if the SPF check fails due to a DNS lookup problem.
Discard (reject) mail that SPF deems to be a failure.
Reject messages from senders who are not allowed to use the domain in question.
Discard emails that SPF determines to be softfail.
Reject messages from senders who cannot be confirmed by the SPF system to be allowed to send, or from senders who are not allowed because no SPF record has been issued for the domain in question.
Discard emails that SPF deems neutral.
Reject messages from senders who cannot be confirmed by the SPF system to be allowed to send, or from senders who are not allowed because no SPF record has been issued for the domain in question.
Discard emails that SPF did not determine to be pass.
Reject messages that do not pass the SPF check for any reason (e.g., the sender's domain does not implement SPF, the result of the SPF check is "unknown" status).
In other words, from top to bottom, the weaker the restriction - the stronger the restriction.
v=spf1 ...... ~all
You will see a description of the tilde symbol (softfail), but in order for the recipient to receive mail in this state, you must use the
You will probably have to choose "Discard (reject) mail that SPF deems to be a failure".