How can I accept emails that use an IP address as the domain in the from header?

This article applies to:

• Trustwave MailMarshal (SEG) 

Question:

• How do I configure MailMarshal SMTP to accept emails that include an IP address in the from field?

Procedure:

You can use header rewrite to change the IP address to a domain name.

NOTE: The Header Rewrite rule will need to be adjusted for the problem email you are seeing.

In the global Header rewrite:

1. On the field matching window check the Envelope return path and From boxes.
2. Select Entire Line from the Field parsing method drop down list and click Next.
3. Enter
   •  (.+)@\[127\.0\.0\.1\] in the Field Search Expression field, where the IP address is the IP address of the sender.
   • $1@domain\.com in the Substitute into field using expression field, where $1@domain\.com is the domain name of the sender that you want to substitute for the IP address.
4. Test the rule