Why You Should Stop Using a Shared IP Address

From the time we’re little kids, we are taught to share. We share our gum, we share rides, we share an umbrella in the rain. But for an email marketer, there are times when you shouldn’t share—especially when it comes to sharing an IP address.

So what is a shared IP address? It’s an IP address that is used by more than one sender to deploy their emails. Shared IP addresses are most commonly used by seasonal or one-off mailers, who typically don’t have a lot of volume to send; therefore sharing is in their best interest since they don’t need to warm up the IP address. Unless you’re part of this group, you should acquire a dedicated IP address that belongs to you, and you alone.

What’s wrong with using a shared IP address?
With a shared IP address, you don’t have complete control over your reputation. Instead, your reputation is only as good as the weakest sender on your shared IP address. Reputation is a huge factor for mailbox providers in determining whether to filter your email to the junk folder or block it altogether. If they choose to block you, your customers will never even see your messages, and that’s going to hurt your bottom line.

If you suddenly experience bulking or blocking at a mailbox provider, it can be extremely difficult to pinpoint the root cause of deliverability issues since you don’t know the other senders on your IP address and you don’t know anything about their emails or list hygiene. Without that visibility, there isn’t much you can do to mitigate a deliverability issue. So if one sender has a complaint problem, it will affect everyone else and drag down their inbox placement rates as well.

Take this example:

Sender A: 1,000 sends, 400 complaints

Sender B: 1,000 sends, 200 complaints

You: 1,000 sends, 0 complaints

Even though you have zero complaints, your complaint rate is 20% (600 complaints out of 3,000 sends) because you’re on a shared IP address. That rate is high enough for mailbox providers to consider moving your messages to the spam folder or worse, rejecting them from your subscribers’ inboxes.

You could be the best sender on the shared IP address and it would be irrelevant to the mailbox providers if another sender isn’t maintaining email best practices and doesn’t have a clean list. As a result of one sender’s neglectful practice, everyone else on the IP address is negatively impacted.

Benefits of a dedicated IP address
Opting for a dedicated IP address gives you complete control over your sender reputation. It allows you to sign up for IP-based feedback loops to directly receive reports on subscriber complaints.

In addition, having a dedicated IP address means you can measure and interpret your own reputation in products like Reputation Monitor, part of Return Path’s Email Optimization solution (illustrated in the image below). Reputation Monitor provides insights into the health and performance of your IP address–and with a dedicated IP address, those metrics are tied directly to you. This allows for more granular monitoring and quicker resolutions to any delivery issues.


Source: Return Path Reputation Monitor

Senders on a dedicated IP address can also apply to Return Path’s Certification program, which offers benefits at global mailbox providers and others who partner with us.

Who should have a dedicated IP address?
It’s up to you as a sender to assess your situation and determine whether you need a dedicated IP address. Here are a few of the many guidelines that can help you determine whether a dedicated IP address is right for your business:

  • You have enough consistent send volume to sustain an IP address on your own. There are no clear-cut numbers on what constitutes enough volume and frequency, but it should be sufficient that you don’t need to warm up your IP address every time you send. As a rule of thumb, if you aren’t sending at least 50,000 emails per month and mailing at least once every 30 days, stick with a shared IP address.

  • You can afford the cost and maintenance of having a dedicated IP address. If your business can’t easily absorb the additional costs associated with a dedicated IP, you may want to hold off.

As an email marketer, you’re accountable for your company’s sender reputation. A poor reputation leads to an ineffective email program, which ultimately impacts your bottom line. With a dedicated IP address, you have complete control over your reputation, and you also have access to numerous tools to help keep it pristine. For most senders, the choice is clear—ditch the shared IP address!

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