You play by the rules. Your list is confirmed opt-in. You have written a compelling message and an inspiring call to action. Your graphic designers have created a stunning custom email.
You then blast the email and achieve deliverability rates lower than you anticipated. You investigate and find that none of your targeted recipients at a major Internet Service Provider (ISP) received your email. This is a disappointing outcome, to say the least. You decide to look into this as a way to avoid low email delivery rates in the future.
Your research reveals that the ISP has blacklisted the IP address that you share with numerous other customers of your Email Service Provider (ESP) because another email marketer sent out an email blast that generated too many spam complaints. Thus, your email delivery rates were lowered by the actions of someone else.
You may be surprised that most ESPs have a very small pool of IP addresses. They reserve these for large customers. In many cases the only way that small companies or non profits can get these addresses is to pay extra or switch to an ESP that offers them as a standard feature.