You can enable SMTP forwarding as a method for adding messages to the Barracuda Message Archiver, and also specify trusted hosts so that the Barracuda Message Archiver accepts only those messages forwarded by trusted (whitelisted) hosts. You enable SMTP forwarding on the MAIL SOURCES > SMTP page. When enabled, and one or more IP addresses are listed as trusted, mail is accepted only from the listed IP address; mail is blocked and not archived if the source is from an IP address not listed in this section. When disabled, and one or more IP addresses are listed as trusted, mail coming from a listed IP address is accepted no matter the domain present in the SMTP envelope of the inbound mail, and mail coming from an IP address not listed in this section is rejected if the SMTP envelope does not contain a domain listed in the Local Domains section on the BASIC > IP Configuration page.
Trusted SMTP Servers
Trusted forwarding servers are those servers whose messages are to be accepted and archived by the Barracuda Message Archiver. When SMTP forwarding is enabled on the MAIL SOURCES > SMTP page, add the IP addresses of all trusted forwarding servers that will send messages to be archived in the Trusted SMTP Servers section of the page. All messages arriving from the servers listed here are always added to the archive regardless of the domain name present in the SMTP envelope. Any messages forwarded from servers not in this list are rejected.
If you are using Microsoft Exchange and are using Envelope Journaling to send messages to the Barracuda Message Archiver via SMTP, add the IP address of each Exchange Server to this section.
If no IP addresses are listed in this section, the Barracuda Message Archiver accepts email for domains listed in the Local Domains section on the BASIC > IP Configuration page if that domain is present in the SMTP envelope of the inbound email.