IP Addresses and Domain Names Play a Major Role in Email Deliverability

Although there are a number of factors that determine your email deliverability, the Internet Protocol (IP) address and domain name you use to send your emails play an important role. The IP address is a numeric label that uniquely identifies every computer/sending source and essentially serves as the pipe through which email is sent to your list of recipients.

To help reduce costs, many email service providers (ESPs) share a limited number of IP addresses among a large number of their client users. So if your organization shares an IP address with other companies – some of which may have less than desirable email practices – there’s a possibility your IP address and domain name could end up with a bad reputation, simply due to others who are sharing your IP address. The worst case is your IP address ends up with a bad reputation or exhibits behavior that appears to demonstrate poor email practices, and then it could be blacklisted or blocked by some Internet Service Providers (ISPs). That means that even if your emails are following email good practices, ISPs such as Google and Yahoo could block your emails. So the more companies sharing IP addresses with you, the higher the probability that your company could suffer from a bad reputation due to others. We frequently see this issue when new clients ask us to review their deliverability.

To improve your control over your reputation, ESPs offer companies their own dedicated IP address. In that case, you “live and die by your own sword.” In other words, only your company’s email practices will determine your email reputation.

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