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Using the Block and Accept Filters 61

What Happens if your Domain or IP Address is on a Blacklist

If your domain or IP address is on a blacklist that you subscribe to, then your Barracuda Spam

Firewall will not deliver messages from users on that domain. There could be several reason why your

domain is on the list:

• Your mail server may have been hijacked by a spammer to be used for spamming.

• Your mail server is an open relay meaning any one can use it to send e-mails to any recipient

without any authentication.

• Spammers used your domain as a fake sender to send spam to recipients.

• If your domain or IP address is on a blacklist, you will need to contact the blacklist

provider to have it removed.

IP Address Filters

IP Block/Accept allows you to filter messages based on the sender’s IP network.

The following table describes the filters on this page.

relays.ordb.org ORDB.org is the Open Relay Database. ORDB.org is a non-profit

organization that stores IP-addresses of verified open SMTP relays.

These relays are likely to be used as conduits for sending unsolicited

bulk e-mail. By accessing this list, system administrators are allowed to

choose to accept or deny e-mail exchange with servers at these

addresses.

bl.spamcop.net SpamCop is a more aggressive spam service that often errs on the

side of blocking mail. Many mail servers can operate with blacklists in

a tag-only mode, which may be preferable when using SpamCop.

Table 5.3:

Filter Description

Allowed IP Range Add any IP addresses or networks that you wish to add to your

whitelist. To add an individual IP address, use a netmask of

255.255.255.255.

Whitelisted IP addresses bypass spam scoring as well as all other

blacklists, but do go through virus, attachment, body, and subject

filters.

Click Add after adding each entry, followed by Save Changes.

Table 5.2:

Blacklist Service Description

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 141 142

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