Summary
You want to block emails with empty sender address.
Details
Before the configuration, understand that emails have envelope and header senders.
The following is an example of an envelope sender:
MAIL FROM:<admin@example.com>
250 2.1.0 Ok
RCPT TO:<test@domain.com>
250 2.1.5 Ok
An example of a header sender:
From: admin <admin@example.com>
To: test <test@domain.com>
To block emails with empty sender address:
- Log in to the IMSVA Linux Shell.
- Use “vi” to edit /opt/trend/imss/config/imss.ini using the command:
# vi /opt/trend/imss/config/imss.ini
- Search for “blockEmpty”. When you see the parameter blockEmptyMailFrom, set the value to “yes”:
blockEmptyMailFrom = yes
- Save the file and restart imssd using the following command:
# S99IMSS restart
- On the Web management console, go to Policy > Policy List.
- Click Add > Other to add a new rule.
- Set the senders and recipients as you want (Here senders mean envelop senders.). Click Next.
- On the Select Scanning Conditions page, click Header keyword expressions.
- Select From then click Add to add a keyword expression.
- Add the content as “^(\s)*$” (without the quotation marks).
- Choose an action for these mails. In this scenario, select Quarantine to block the empty header sender.
- Provide a name for this rule.
