Can I greylist only connections from IPs that are on an RBL?
It is possible to enable greylisting only for messages from IP addresses that fail a realtime black list lookup. To do so, you would need to enable and set the greylisting values you want to use, then disable greylisting and enter a Sieve script to enable it only for IPs that fail an RBL test. To do so, follow these steps:
- Log into the SecurityGateway site with an global administrator account
- Click Security on the left-hand menu
- Locate the Anti-Spam section
- Click Greylisting
- Check the box for 'Enable greylisting'
- Set the values you wish to use for the amount of time the delivery attempts will be refused and the expiration of records
- Click Save
- Uncheck 'Enable greylisting'
- Click Save
- Locate the Advanced section under Security
- Click Sieve Scripts
- Click New
- Enter a name for the script, such as 'Greylist DNSBL matches'
- For Mail Event, select 'RCPT'
- Select the scope you wish to use - Global or Domain
- If you selected Domain above, select the specific domain to which you wish to apply the script
- Enter this script into the Script Text box: require ['securitygateway']; if not lookup 'rblip' 'all' {greylist;}
- Click 'Save and Close'