If you are sending more than one type of email to your customers, such as marketing and transactional, it is often a good idea to separate the IPs that you send these emails from in order to get better deliverability and email engagement tracking.
One way of segmenting your email sends is to use our IP Pooling feature to send your different email types through different IPs. These IPs can be Whitelabeled to your domain, so the receiving mail servers have no questions about who sent the emails.
You can also segment your email sending by subuser, which will allow you to share the same overall email credit pool but have unique SMTP credentials, settings, statistics, and site login. Subusers can also be Whitelabeled to separate sending domains by purchasing additional sending IPs and assigning a subuser to that IP. More information on segmentation via subusers can be found here.