Before we start, it’s important to note that it’s normal to fluctuate between an “average” and “good” reputation. If you have a big campaign coming up, and you need to send a lot of emails to a segment that’s not as engaged, this will lower your reputation for a bit. That’s a normal part of the business.
Sender reputation is made up of a combination of two factors: IP reputation and domain reputation. These are calculated separately, but they both have a big impact on deliverability.
What is IP reputation?
All emails are sent from a computer or a server that has a unique identifying address (their IP address). It’s easy to tie this IP address to specific senders, so an IP address gives ISPs a straightforward way to track senders.
IP reputation is based solely on the IP address where the email originated from. It’s not connected to the brand that’s sending the email.
IP reputation is what gets you into the recipient server. As a mail sender, you typically either have a dedicated IP address, or you send from a shared IP pool.
What’s a dedicated IP address?
A dedicated IP address means that all your emails are routed through a single IP address. This IP address is not used by others, so you are solely responsible for what is sent from it.
With a dedicated IP address, deliverability rests entirely on you. If you follow best practices, this can be a good thing. But mistakes can have a bigger impact and can take longer to recover from.
If you want to whitelist your IP address, this is much easier to do with a dedicated IP address.
Dedicated IP addresses typically make more sense for larger businesses with high volumes of emails, since they typically have the resources required to ensure best deliverability practices.
What’s a shared IP pool?
A shared IP pool consists of several companies sharing a number of IP addresses for sending emails. This means that deliverability is a shared responsibility. Someone else’s bad practices can negatively impact your deliverability, but you can also benefit from increased email volume.
Smaller companies might not be able to maintain the email volume necessary to achieve a good sender reputation. By using a shared IP pool, their email volume is increased due to the emails sent by other companies, which boosts everyone’s sender reputations.
A shared IP pool also protects smaller senders from costly mistakes. If one small sender in a shared IP pool makes a mistake, it won’t have as big of an impact on them simply because there is so much more email volume coming from the shared IP pool. If they were to make the same mistake from a dedicated IP address, it would be harder to recover from.
Smaller senders will typically use a shared IP pool. The benefits of a dedicated IP address usually don’t apply to companies who aren’t sending very large volumes of email.