User guide

User Guide 139
Proxy Settings
POP 3 proxy: Deny unsafe file name patterns
If you want to deny certain file name attachments, select the Deny unsafe file name patterns check box. This
is a list of file names or types that you want the proxy to block. Use the asterisk (*) as a wild card. For example,
if you want to block all MP3 files, type
*.mp3. If you read about a vulnerability in a LiveSecurity Service Alert
that affects PowerPoint files and you want to deny them until you install the patch, type
*.ppt.
1. To add file name patterns to the blocked list, enter the pattern and click Add.
2. To remove a file name pattern from the blocked list, select the pattern and click Remove.
3. Click Submit.
About the SMTP proxy
SMTP (Simple Mail Transport Protocol) is a protocol used to send email messages between email servers and
also between email clients and email servers. It usually uses a TCP connection on port 25. You use the SMTP
proxy to control email messages and email content. The proxy scans SMTP messages for a number of filtered
parameters, and compares them against the rules in the proxy configuration.
With an SMTP proxy filter you can:
Adjust timeout, maximum email size and line length limit to stop the SMTP proxy from using too many
network resources and can prevent some types of attacks.
Customize the deny message that users see when an email they try to receive is blocked.
Filter content embedded in email with MIME types and name patterns.
Limit the email addresses that email can be addressed to and automatically block email from specific
senders.
To enable the SMTP proxy, see Enable a proxy
. Then, if you choose, edit the proxy definition as described in
Add or edit a proxy policy
.
For information about the settings on the Incoming tab, see Set access control options
.
For information about the settings on the SMTP Settings tab, see:
SMTP proxy: Proxy limits
SMTP proxy: Deny message
For information about filtering messages based on email addresses or content see:
SMTP Proxy: Filter email by address pattern
SMTP proxy: Email content
If you have a second SMTP email server, you must have an additional external IP address to give to the Edge.
You can then enable 1-to-1 NAT
and make a custom incoming proxy policy for SMTP.