Product manual

GFI MailEssentials 7 Anti-Spam | 107
Option Description
Automatically check for
updates
Configure GFI MailEssentials to automatically check for and download any Anti-Phishing
updates. Specify the time interval in minutes when to check for updates.
NOTE
It is recommended to enable this option for Anti-Phishing to be more effective in
detecting the latest phishing trends.
Enable email notifications
upon successful updates
Select/unselect checkbox to be informed via email when new updates are downloaded.
Enable email notifications
upon failed updates
Select/unselect to be informed when a download or installation fails.
Download updates now Click to immediately download Anti-Phishing updates.
NOTE
You can download updates using a proxy server. For more information, refer to Proxy
settings (page 221).
5. Click Actions tab to select the actions to perform on messages identified as spam. For more
information, refer to Spam Actions - What to do with spam emails (page 135).
6. Click Apply.
7.1.3 Directory Harvesting
Directory harvesting attacks occur when spammers try to guess email addresses by attaching well
known usernames to your domain. The majority of the email addresses are non-existent.Spammers
send emails to randomly generated email addresses and while some email addresses may match real
users, the majority of these messages are invalid and consequently floods the victim’s email server.
GFI MailEssentials stops these attacks by blocking emails addressed to users not in the organizations’
Active Directory or email server.
Directory harvesting can either be configured to execute when the full email is received or at SMTP
level, that is, emails are filtered while they are being received. SMTP level filtering terminates the
email’s connection and therefore stops the download of the full email, economizing on bandwidth and
processing resources. In this case the connection is terminated immediately and emails are not
required to go through any other anti-spam filters.
This filter is enabled by default on installing GFI MailEssentials in an Active Directory Environment.
Directory Harvesting is set up in two stages as follows
Stage 1 - Configuring Directory Harvesting properties
Stage 2 - Selecting if Directory Harvesting should be done during the SMTP transmission.
Stage 1 - Configuring Directory Harvesting properties
1. Go to Anti-Spam > Anti-Spam Filters > Directory Harvesting.