Question
How to configure Greylisting in Plesk?
Answer
Greylisting configuration is not possible via Plesk web-interface, but only with Plesk CLI.
Note: Greylisting feature is available only in Plesk for Linux.
Parameters like expire-interval, grey-interval, penalty-interval, and others are configured via the utility plesk bin grey_listing. Run the utility with --info-server to display configuration settings:
# plesk bin grey_listing --info-server
Grey listing configuration.
Grey listing checking disabled
Grey interval 5 minutes
Expire interval 51840 minutes
Penalty interval 2 minutes
Penalty disabled
Personal grey listing
configuration allowed
Server-wide black list:
Server-wide white list:
White domains patterns list:
Black domains patterns list:
*[0-9][0-9]-[0-9][0-9]-[0-9][0-9]*
*[0-9][0-9].[0-9][0-9].[0-9][0-9]*
*[0-9][0-9][0-9]-[0-9][0-9][0-9]-[0-9][0-9][0-9]*
*[0-9][0-9][0-9].[0-9][0-9][0-9].[0-9[0-9][0-9]*
dsl|pool|broadband|hsd
dynamic|static|ppp|dyn-ip|dial-up
SUCCESS: Gathering of server wide information complete.
Black/White lists for Greylisting are configured server-wide and per individual mail account in GUI.
Server-wide Greylisting White/Black lists are configured on the page Spam Filter Settings at Tools & Settings > Spam Filter Settings .
Greylisting White/Black lists configuration per mail account: Domains > domain name > Mail Accounts > jdoe@example.com > Spam Filter.
The page allows to add email addresses only. To add the domain localhost to the White list, try adding the address *@localhost.
Alternatively, Plesk CLI grey_listing can be used to configure the spam filter. For example, to add the domain to the server-wide White list:
# plesk bin grey_listing --update-server -domains-whitelist add:*@domain.tld SUCCESS: Update of server-wide settings complete.
To add the domain example.com to the Greylisting White list for the mail account mail@domain.tld:
# plesk bin grey_listing --update-mailname mail@domain.tld -domains-whitelist add:*@example.com
SUCCESS: Update of mail 'mail@domain.tld' complete.
To get information about Black/White lists on mail accounts for mail@domain.tld:
# plesk bin grey_listing --info-mailname mail@domain.tld
Grey listing configuration for mail@domain.tld
User's black list:
User's white list: *@example.com
SUCCESS: Gathering information for 'mail@domain.tld
Additional information
Greylisting works as follows: the first message is rejected, and the next message sent from the same address (sender server IP address and 'From:') will be accepted after a certain length of time passes.
After the first email is rejected, the sender's address is added to the Greylisting database. The information is stored there for an expiration time interval (expire-interval).
For the message to be accepted, the grey interval (grey-interval) must complete. If the message was sent before the grey interval has passed, the penalty interval (penalty-interval) is added.