You have a Cisco PIX/ASA firewall with Mailguard enabled and are experiencing problems with incoming email.
Known problems include:
- No email is delivered to your ESMTP server
- May cause duplicated incoming messages
To check for the presence of Mailguard, follow these steps:
Note If you have an ESMTP server behind the PIX firewall, you may have to turn off the Mailguard feature to allow mail to flow correctly. Also, you may be unable to establish a Telnet session to port 25 with the fixup protocol smtp command. This is especially true with a Telnet client that uses character mode.
Note On Cisco PIX firewalls with firmware version 5.1 and with later versions, the fixup protocol smtp command changes most characters in the SMTP banner to asterisks. The exceptions to this are the "2" character, the "0" character, and the "0 " character. The carriage return (CR) character and the linefeed (LF) character are ignored. In version 4.4, all characters in the SMTP banner are converted to asterisks.
To work around these issues, turn off the Mailguard feature of the PIX firewall. To do this, follow these steps:
Note For more information about how to turn off the Mailguard feature of the Cisco PIX firewall, visit the following Cisco Web site: