User guide

Chapter 9: Configuring Proxied Services
118 WatchGuard Firebox System
might be inside.salesdept.bigcompany.com, which would become the public
address
bigcompany.com.
1 Click the Masquerading tab.
The SMTP masquerading information appears, as shown in the following figure.
2 Enter the official domain name.
This is the name you want visible to the outside world.
3 In the Substitute the above for these address patterns text box (to the
left of the Add button), type the address patterns that are behind your
firewall that you want replaced by the official domain name. Click
Add.
All patterns entered here appear as the official domain name outside the Firebox.
4 In the Don’t Substitute for these address patterns text box (to the left
of the Add button), type the address patterns that you want to appear
“as is” outside the firewall. Click Add.
5 Enable the checkbox marked Masquerade Message IDs to specify
that message IDs in the Message-ID and Resent-Message-ID header
fields are converted to a new ID composed of an encoded version of
the original ID, a time stamp, and the host name entered in the
domain name field described in step 2.
6 Enable the checkbox marked Masquerade MIME boundary strings to
specify that the firewall converts MIME boundary strings in messages
and attachments to a string that does not reveal internal host names or
other identifying information.