The familiar IP address format (like 198.51.100.0) is very close to running out. A new format of IPs (which looks like 2001:DB8:3742:823e:3b02:76:982b:463) has been introduced with a huge capacity, capable of providing unique internet addresses not just to our servers, computers and phones, but also the growing number of Internet-connected devices, such as cars, TVs, fridges, and even light bulbs.

The old format is called IPv4, while the new format is called IPv6.

Email has been slow to adopt IPv6. Sender reputation works better on the small IPv4 ranges where senders can be tracked and monitored, and reputation can be built. It’s difficult to build an IP allowlist or blocklist on IPv6 when there are approx. 340 billion billion billion billion, addresses available.

Demand for IPv4 IPs has not gone away so it’s increasingly difficult and expensive to acquire new IPv4 addresses. As Emarsys continues to grow, we need additional IPv4 addresses for our clients’ emails. Currently our IP address supply is dependent on our Internet provider, creating a risk to our ability to scale and meet our clients’ needs.

To protect against this risk and have control of our IPs, Emarsys has invested in our own IP ranges. This is a significant project and investment which is being planned, managed and coordinated by our System Engineering teams.

This means is that IP addresses will be migrated from the old rented ones to the new Emarsys-owned ones.

This work is ongoing. IPs will slowly be integrated into our sending pools, warmed up behind the scenes and slowly put in place of the old rented IP ranges. This IP migration work is being carried out by the System Engineering teams, supported by the Deliverability team.

Not much. Most of the work will happen invisibly, and for most of our clients the only thing they will see is that some of our internal documentation will be updated as our IP ranges change.

There are certain scenarios where a client may have to make small changes:

1. If there is a legacy issue on an account, such as invalid domains, these will need to be reviewed and brought up to current standards.
2. If the client has dedicated IP addresses, they may wish to update their own internal documentation or need to update their internal allowlists.
3. If the client has Return Path Sender Score Certification, those registered IPs will need to be updated.

Anyone who falls into one of the above three scenarios will be contacted by us directly with the information needed to make the required changes.

This page will be kept up to date with all the latest information.