User guide

User Guide 137
Proxy Settings
Maximum email line length
This setting prevents some types of buffer overflow attacks. It is unlikely that you will need to change
this setting unless it prevents access to legitimate mail.
Deny Message
In the Deny Message field, you can write a custom plain text message that will appear in the recipient
email when the proxy blocks that email. You can use these variables:
%(type)%
Puts the content type of the email.
%(filename)%
Puts the name of the attached file.
%(virus)%
Puts the type of virus found.
%(action)%
Puts the action taken by the proxy policy.
%(reason)%
Puts the reason the proxy policy denied the content.
%(recovery)%
Puts whether you can recover the attachment.
It is important to know how the POP3 proxy denies email. When the proxy blocks a message because of a
header, you get a deny message instead of the email. When the proxy blocks an email message because of
body or attachment content and the email is less than 100 kilobytes, you get a deny message instead of the
email. If the proxy blocks an email message because of body or attachment content and the email is larger
than 100 kilobytes, you get a truncated version of the email or attachment and the deny message is attached.
When the POP3 proxy detects a protocol anomaly, or the email line length exceeds the maximum email line
length, the proxy blocks the message download and the user gets no notification. You can see deny messages
for this in the log messages. For information on using the log message tool, see the topic About logging and
logfiles.