High-volume users (on plans of 100,000 emails per month and above) who purchase additional IP addresses may assign SMTP usernames, authenticated email / IP addresses, API keys, and Subaccounts to an IP pool. This will help spread email load among the IPs in the IP pool.
How to add an IP Pool
To do this, create the necessary pools via the "Settings > Dedicated IPs" section of the App by selecting the "Add New Pool" button towards the bottom of the page.
You can then add an IP to the pool using the "Add IP address" button or use the drop-down arrow on right side of the page of an existing IP and choose the "Move to pool" option to assign it to a specific pool.
Assigning SMTP Users, IP Addresses, API Keys, or Subaccounts to an IP Pool
Each pool can be assigned to specific SMTP Users, IP Addresses, API Keys, or Subaccounts via the following sections of the App:
SMTP Users
Sending > SMTP Users > Select the User > SMTP Details > IP Pool
IP Authentication
Sending > IP Authentication > Select the IP Address > IP Address Details > IP Pool
API Keys
Sending > API Keys > Select the API Key > API Details > IP Pool
Subaccounts
Settings > Subaccounts > Select the Subaccount > IP Pool
Example for an SMTP User:
Additional information
Users sending various types of email in bulk should consider creating IP pools as a means to further maximize deliverability. For instance, creating an IP pool for marketing emails and another IP pool for transactional emails is a great way to ensure important emails land in the inbox (transactional mail), while taking measures to improve engagement for other emails more prone to getting snagged by spam filters (marketing mail).
If you have questions or need assistance with IP pools, please reach out to our support team.