Greylisting is a prevention method that allows to filter out spammers with special programs. Graylisting is active for all the messages by default (except those specified in white list).
The receiving mail server rejects a message, informs a sender that the message cannot be delivered immediately and asks to try again later. The sending server of a legitimate user will retransmit the message. Such mail servers are put on the white list and their will be delivered without any delay.
The servers that spammers use generally will not response, because the spammer's goal is to disseminate millions of messages quickly and not have to keep track of those failed to reach their destination.
Greylisting is running through such applications, as Milter-greylisting and Postgrey (go to the Applications module to enable them).
If you run Postgrey, the Greylisting module will be available only for the administrator.
View white lists
- Sender - mail server's IP-address, network address with a mask, e-mail domain or e-mail address.
- Recipient - possible variants:
- e-mail address - the rule will be applied to all the messages from this e-mail address.
- mail domain - the rule will be applied to all the messages sent to any mailbox of a certain Mail domains. The value should start with "@", such @example.com.
- all - the rule will be applied to all the incoming messages.
Please note, that the "Recipient" column is not displayed, if you run Postgrey.
Add rule into the white list
To add a new rule to the white list, click the "New" icon and fill out the form:
- Sender type - select a desired type:
- IP-address - the IP-address from which the message was sent will be checked. You can provide a block of IP-address using a mask.
- Domain name - the value specified in the sender's e-mail address after "@" will be checked.
- E-mail address - the sender's e-mail address will be checked.
- Sender - enter a sender's value according to the type provided above, e.g. 126.96.36.199, 188.8.131.52/24, example.com or email@example.com.
- Recipient type - select a desired type:
- Common rule - this rule will be used to check all the incoming messages. Such a rule can be created by the control panel administrator only.
- Domain name - the value provided in the recipient's e-mail address after "@" will be checked. Both the control panel users and administrators can add this type of rules.
- E-mail address - recipient's e-mail address will be checked. This field is available both for administrators and users.
- Recipient - enter a value corresponding to the receiver type specified above, e.g. example.com or firstname.lastname@example.org.
Please note, that the "Recipient" and "Recipient" type columns are not displayed, if Postgrey is used
Edit white list parameters
To edit a white list, locate the white list you wish to edit, click the "Edit" icon and modify the settings you want to change.
Delete white list rules
To delete a white list rule, select it from the list and click the "Delete" icon. Confirm that you want to delete the selected white list rules by clicking "OK" in the following window.