source: https://www.securityfocus.com/bid/1999/info

Network Associates WebShield SMTP is an email virus scanner designed for internet gateways.

In the event that WebShield SMTP receives an outgoing email containing six "%20" followed by any character within the recipient field, the application will crash, resulting in an access violation error upon processing of the email. Restarting WebShield SMTP is required in order to regain normal functionality. It has been unverified as to whether or not arbitrary code can be executed on the target system if specially crafted code is inserted into the buffer.

recipient@f%20f%20f%20f%20f%20f%20f