We use MailChannels to use high-reputation IPs to send emails to avoid blacklisted IP issues. That means your email will always be sent from high-reputation IPs regardless of the IP address included with your hosting package.
The most common reasons for IP Addresses getting blacklisted are outbound spam and transmission of malicious files. When a rogue user or a compromised script sends out spam emails or transmits malicious files, the server IP gets blacklisted.
We have a zero-tolerance policy against spam and stringent protection to prevent spam outbreaks so that our IP Addresses do not get blacklisted. MailChannels Outbound Spam Filter strips out spam and malicious files before they leave our network. This, in turn, helps keep our IP Addresses clean from getting blacklisted.
MailChannels is included for free with our Web Hosting, Reseller Hosting, and Semi Dedicated Hosting packages.