Email service providers treat domains differently based on their reputation. This “score” can be based on many things, such as the age of the domain name, how well the sending account has been set up, deliverability, engagement data from users receiving email from it, and – often to a higher degree – previous listings of domain names and IP addresses on anti-spam services such as SpamHaus.
You can use MXToolbox to check your domain and IP reputation against many popular block lists.
If any of your domains is blacklisted, we highly recommend letting it rest for a couple of days and wait until it’s delisted. You can use your other sending profiles for your campaign while you rest your blacklisted domain/s.
If any of your IP is blacklisted, contact your CSE and request for IP replacement in your sending profile if you still have good IPs available to be used.
If you wish to add extra domains/IPs, feel free to contact your CSE. Each domain is $15/year and each IP is $15/month.