The “Rspamd Antispam” module is located in the “Mail” menu. It is used to determine whether an email is spam, in which case the subject of the email will be changed; and emails like this will be rejected. When you open the module, the main window displays the status of the “Rspamd Anti-Spam” service with the possibility to “Disable” (or “Enable” if the service is disabled) and service settings.
The “Scan mail” flag activates the service.
The “The number of points at which SPAM header is added to the message” field allows you to set a threshold at which the email will be considered spam, and the subject of the email will be changed. A threshold of zero indicates that all emails are spam.
The “The number of points at which mail is rejected” field allows you to set a threshold at which the message will be considered spam and will be rejected. A threshold of zero indicates that all emails are spam.
The “Enable SPF check” flag enables additional SPF checking.
The “Enable SURBL check” flag enables additional SURBL checking.
The “Skip mail check from networks” field is intended for specifying networks the emails of which will not be subject to antispam checks.
Learn more about Rspamd - https://rspamd.com/doc/.