Question Plesk Email Security Block list doesn't work

[Paul L]

Server operating system version

Ubuntu 22.04.3 LTS

Plesk version and microupdate number

18.0.54 Update #3

The domains set in my block list in Plesk Email Security (Extensions/My Extensions/Plesk Email Security/Open/Server Settings/Blocklist) are not being blocked.

Among others, I have added @.ru and @.su to the list and yet continue to receive emails with these TLDs.
I have set the Spam action to 'Mark', not to 'Block'. Does the Blocklist work regardless of this setting or do I need to set the action to 'Block'? I am concerned that, if I do, this then blocks all suspect emails (according to Plesk's assessment of what is spam or not) and not just the blocklist entries. If it blocks all suspect emails then this could result in wanted emails, such as those containing many hyperlinks, not being delivered.

 

[Kaspar]

@Paul L welcome to the Plesk forums.

The name "Blocklist" might be a bit confusing, as any email that matches a blocklist entry gets treated as spam and follows whatever action you've set in the "spam action" setting. So if you've set the spam action to 'Mark', then that means that all emails received from @.ru and @.su TLD's will be marked as spam. Changing the "spam action" setting to 'Block' will reject any email that's considered spam.

There currently is no option in Plesk to completely block (reject) emails received from specified TLD's. You could however, at your own risk, adjust the Postfix configuration on you server in to block emails from specified TLD's. If you'll Google for "postfix block tlds" there are plenty of results that explain how you can adjust Postfix.

 

[Paul L]

@Paul L welcome to the Plesk forums.

The name "Blocklist" might be a bit confusing, as any email that matches a blocklist entry gets treated as spam and follows whatever action you've set in the "spam action" setting. So if you've set the spam action to 'Mark', then that means that all emails received from @.ru and @.su TLD's will be marked as spam. Changing the "spam action" setting to 'Block' will reject any email that's considered spam.

There currently is no option in Plesk to completely block (reject) emails received from specified TLD's. You could however, at your own risk, adjust the Postfix configuration on you server in to block emails from specified TLD's. If you'll Google for "postfix block tlds" there are plenty of results that explain how you can adjust Postfix.

Thanks Kaspar, I've set the action to Block.
You say that there currently is no option in Plesk to completely block (reject) emails received from specified TLD's, but I have added @.ru and @.su to my block list in accordance with the instructions under the block list box. Does this not block the TLD?

 

[Kaspar]

Thanks Kaspar, I've set the action to Block.
You say that there currently is no option in Plesk to completely block (reject) emails received from specified TLD's, but I have added @.ru and @.su to my block list in accordance with the instructions under the block list box. Does this not block the TLD?

What I meant to say was that there is no option in Plesk to only block (reject) emails received from specified TLD's. If you've set the Spam action to 'Block' then everything listed in the blocklist will be blocked, but so will every other email that's considered spam. I hope this clarifies my previous post a bit.

 

[Paul L]

What I meant to say was that there is no option in Plesk to only block (reject) emails received from specified TLD's. If you've set the Spam action to 'Block' then everything listed in the blocklist will be blocked, but so will every other email that's considered spam. I hope this clarifies my previous post a bit.

Thanks, yes, perfect.

Another question for you, I have noticed that there's another spam filtering resource within Plesk at Tools & Settings / Mail / Mail Server Settings / Black list. I have previously (before changing the above Action setting in Extensions/Plesk Email Security) populated this with many domains but it does not seem to exclude any of them. Is this linked to Plesk Email Security in some way or independent? If independent, have you any idea why it does not work?
Presumably, now that the Plesk Email Security blacklisting is (hopefully) working properly, I do not need to duplicate backlisting in this area since all will be covered already. However, I am curious as what this resource is and why it's needed/provided alongside Plesk Email Security.

 

[Kaspar]

Yes, the black list at Tools & Settings > Mail Server Settings works independent of Plesk Email Security. It can only be used to block (reject) emails from added domains (not tlds or full email addresses). It has some overlap with the Blocklist function from Plesk Email Security. The caveat however is that blocking (rejection) is based the envelope sender (also known as Return-Path) of an email. Not the specified From address of an email.