A protocol used to eliminate email forgeries. A line of code called an SPF record is placed in a sender’s Domain Name Server information. The incoming mail server can verify a sender by reading the SPF record before allowing a message through.

Combining Email Marketing with Other Types of Marketing
Whether you choose to do your marketing online or offline, one thing does not change. This is the concept that no single marketing strategy will be as effective as a combination of two or more marketing strategies.