How to enable SPF on Trend Micro interscan messaging security virtual appliance?

Modify your Postfix settings to inject SPF checking to the Postfix email message flow.

1. SSH to IMSVA with root credential.

2. Backup /opt/trend/imss/postfix/etc/postfix/master.cf and then modify it with VIM command:

#cp /opt/trend/imss/postfix/etc/postfix/master.cf master.cf.b4spf

#vi /opt/trend/imss/postfix/etc/postfix/master.cf

3. Remove the comments for the following so that the SPF script will be launched by Postfix when needed.

SPFPolicyd unix — n n — 0 spawn user=imss argv=/opt/trend/imss/postfix/etc/postfix/SPFPolicyd/SPFPolicyd.py

4. Backup /opt/trend/imss/postfix/etc/postfix/main.cf and then modify it with VIM command:

#cp /opt/trend/imss/postfix/etc/postfix/main.cf main.cf.b4spf

#vi /opt/trend/imss/postfix/etc/postfix/main.cf

5. Locate smtpd_sender_restrictions key, which looks like below:

smtpd_sender_restrictions = check_policy_service inet:127.0.0.1:999

Change it as below:

smtpd_sender_restrictions = check_policy_service inet:127.0.0.1:999, check_policy_service unix:private/SPFPolicyd

6. Locate SPFPolicyd_time_limit key, remove the comment before it like below:

SPFPolicyd_time_limit = 3600

7. Save the changes.