Our antispam software, which is the only one of its kind in the world, uses PostgreSQL to store rules, parameters and lists attached to each unique email address. While the smtp server is transferring emails, it performs some checks in respect to senders and receivers address/ip/domain etc... and gives a response to the sending server. This requires a very powerful and speedy search of database because we have to reply within 3 seconds to the sending server. It is giving excellent results. I will be available to reply to any questions you may have. Please visit http://antispam.datainfosys.net in case you want to understand more about our antispam technology.
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