A blacklist, as the name implies, could be a list of folks or companies who have met with the disapproval of others. In the net world a blacklist refers to those individuals who are marked as accountable for generating spam in a very very big way. Blacklists are referred to as blocklists.
Blacklists are used to combat spam in a very terribly specific way. When spam is reported to one of the relevant spam fighting organizations the IP address the spam originated from is added to a banned or blacklisted IP addresslist. An IP address is the distinctive location of you or your web site on the web - assume of it as your "home address" online. To put it merely each http://www.domain.com Internet address features a matching IP address. Any email coming back from your web site domain conjointly has a corresponding IP address. If your IP address is present on a blacklist then you are potentially wasting it slow sending email to customers.
Why are you wasting some time? Fashionable spam blockers come back with the foremost common blacklists installed and/or allow you to import updated blacklists into your spam blocker. This enables to you block a large quantity of spam however you will also, potentially, block legitimate email. Blacklists aren't foolproof.
There are two varieties of IP address:
Dynamic - changes each time you connect to the Internet. Most ordinarily used for dialup Net access. Spammers love these as a result of they're very hard to trace and a hundred% disposable.
Mounted/Static - All websites, most massive firms and a few people use fastened IP addresses. This could cause huge issues if they're reported for spamming.
When an IP address (dynamic or fixed ) is reported for sending spam it's added to a blacklist. There are 3 totally different sorts of blacklists:
Temporary
An IP address placed on a short lived blacklist can have email coming back from that IP address blocked for several hours.
Once some hours the offending IP address is removed from the blacklist.
Permanent
When an IP address is added to a permanent blacklist any email server configured to dam email from this list will never receive email from that range of IP addresses again.
Comprehensive
This is the most damaging of blacklists. Not solely does it block a single IP address it also blocks the IP addresses next to it. For example if the IP address 192.156.66.sixty seven was added to a comprehensive blacklist then all IP addresses close to 192.156.66.sixty seven will additionally be blocked. This could be a huge problem for those web site owners using virtual hosting as a result of if your host has ever appeared on a blacklist then you are also on the same blacklist, by default, as a result of of the shared hosting from the same IP range.
It is vital for all web site homeowners to test whether or not they're on a blacklist. You'll want your IP address (accessible from your webhost) and you'll check your blacklist status at: www.mail-abuse.org/cgi-bin/lookup
Blacklists are a necessary evil because of the amount of spam being sent every day but aren't an actual science. Take a few moments from your day and ensure that your website or email address isn't being blocked.