Has your IP address been black listed?
In Constant Contact's recent S1 SEC filing of its intention to become a public company, it prominently discloses in the Risk Factors section that some of itsá "Internet protocol addresses currently are listed with one or more blacklisting entitiesà" This shouldn't come as a surprise because every e-mail service provider at one time or another has had to deal with black lists. As with every issue, there are pros and cons.
Then and now
When e-mail service providers were in their infancy, regardless of their clients' e-mail volume, they assigned numerous clients to a single IP address creating management efficiencies with their mail servers. Over time, spam pushed reputation management to the top of most e-mail marketers' agendas creating a demand for unique IP addresses.
Since dolling out and managing one IP address per client is less efficient than a one to many system, most e-mail service providers were engaged in forced higher setup and licensing fees. E-mail service providers with a large concentration in the small business market had a hard time selling the concept of a unique IP address to their clients so they decided to take on the task of reputation management with their shared addresses. These two very different approaches to reputation management have created a large rift between the haves and have-nots.
Pros and cons of risk management of IP addresses
The major pro to a shared IP address is that it less expensive because there is no rental fee. Also, the marketer gets an automatic good reputation regardless of their sending history if their e-mail service provider managed the assigned IP address correctly.
Companies need to be aware that a shared IP address has a greater chance of landing on a general black list because of other clients' bad sending practices, which will lower deliverability rates. Ask the e-mail service provider directly if the IP address is shared to be certain. To double check, a black list look-up on one of several Web sites can be conducted. Or for those more tech savvy, a DNS check can be done. Generally speaking, if the deal was cheap or it's too good to be true, the IP address is probably shared.
The bottom line is that you have to give up something to get something. Small companies, with small budgets who don't need to have a high deliverability rate would be satisfied with shared IP addresses. Larger companies, who do not wish to be black listed and need a high deliverability rate, should stick to a unique IP address.