You can have more than one IP addresses provided you can justify their need and functions in your organization. Multiple IP addresses can be obtained if the volume of data you generally handle and send out is extraordinarily large and have to be dealt with in a specific time-frame regularly. Many companies use different IP addresses that are categorized according to definite mail streams. Such companies can do better with multiple IP addresses. You may opt for
multiple IP addresses if you have to manage large job volumes. Your budget and delivery could be the other reasons for using multiple IP addresses.