User`s guide

If your mail server or Barracuda Spam & Virus Firewall is on the public network, you might want to allow your Barracuda Firewall to provide
protection and move your mail system onto the internal network. The mail traffic passes through the Barracuda Firewall in both directions.
If the advertised method of receiving email is se a service such as DynDNS to make a permanent identifiera -assigned IP address, u dynamically
for your mail server or Barracuda Spam & Virus Firewall. For more information on the DynDNS service, see .http://dyn.com/dns/
As you can see on the page, the Any-EMAIL service object contains the following email protocols: POP2, POP3S,FIREWALL > Service Objects
POP3, IMAP, IMAPS, and SMTP. You can use this object or just the protocols that you want to support. The rules below the protocols specify
explicitly. Configure the firewall rules for the cases that match your scenario, and then verify your firewall rule order.
Case 1 – Barracuda Spam & Virus Firewall
Configure a rule to redirect incoming mail traffic for the Barracuda Spam & Virus Firewall. If you have a Barracuda Spam & Virus Firewall and your
mail server does not support POP or IMAP, this is the only rule that you will need for incoming email traffic.
Go to the page and configure the following rule to redirect the incoming mail traffic:FIREWALL > Firewall Rules
SMTP-2-SPAMFW Values:
Action Source Destination Service Connection Redirected To
DNAT Either the nInternet
etwork object or a
specific public IP
address. For
example, the IP
address of the
hosting provider.
The destination
depends on the
advertised method of
receiving email.
If it is one or
more external
static IP
addresses,
enter those
addresses (a
CIDR
summarization
of addresses
can also be
used).
If it is a domain
name which
maps to a
dynamically-ass
igned IP
address, select
the network
object named A
ny .
SMTP No SNAT (the
original source IP
address is used)
The i static IPnternal
address of the
Barracuda Spam &
Virus Firewall.
Case 2 – Barracuda Spam & Virus Firewall and a POP/IMAP Mail Server
If you have a Barracuda Spam & Virus Firewall and you also want to support POP/IMAP traffic from your mail server, then you must add this rule
in addition to the above rule for the Barracuda Spam & Virus Firewall.
Go to the page and configure the following rule to redirect the incoming POP/IMAP traffic only to the mail server:FIREWALL > Firewall Rules
POP-2-INTERNAL Values:
Action Source Destination Service (select
relevant ones)
Connection Redirected To