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>Chapter 1. Background</H1
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>1.1. <A
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>Why Filter Mail During the SMTP Transaction?</A
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>1.1.1. <A
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>1.1.2. <A
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>The Cause</A
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>1.3. <A
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>The SMTP Transaction</A
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> Here we cover the advantages of filtering mail during an
incoming SMTP transaction, rather than following the more
conventional approach of offloading this task to the mail
routing and delivery stage. We also provide a brief
introduction to the SMTP transaction.
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