How is your web hosting provider responsible for blocked emails? It all boils down to something known as an IP address, which is the numerical address of a website. If you are part of a virtual hosting service, (which make up a large majority of more affordable web hosting providers), chances are you are sharing an IP address with hundreds of other clients. Some of these clients might be spammers. If they are what happens is the IP address that they are using, (which is the same as yours and other innocent clients), becomes associated with spam, which causes it to be on a spam blacklist. When an IP address gets on a spam blacklist, it can no longer send emails through that email provider. It doesn't matter if it's the original spammer sending email or someone that is sending email legitimately. Some spam blacklists are temporary, lasting only a few hours, while others cause an IP address to be banned permanently. Then there is a type of spam blacklist known as 'obscene', in which not only is the original IP address permanently banned, but any IP address that could possibly be related to it also gets banned. This means that even IP addresses that have nothing to do with spammers could still be blocked.
What can you do to know for sure your hosting provider's IP address is blocked? First, you could examine the email to see why it was blocked. If this is the case, the headers of the email will tell you so. Another way you can see if your hosting provider's IP address is on a blacklist is through a website known as Dnsstuff.com. You can find this information through their "Spam Database Lookup" section, where you enter either your hosting provider's IP address or your domain name. The website will return which spam blacklists the IP address is a part of, if any.
So, what can you do to prevent this problem? If you are a part of a hosting provider who has an IP address that is blacklisted, you will want to change to another one that will allow each client a different IP address. When individual IP addresses are issued out, it is less likely the web hosting provider will be associated with spam. You will also want a hosting provider that has 24/7 staff dedicated to making sure emails get delivered. Frontier Power Hosting does both of these things at only $97 a month. For more information you can visit their website at Frontierpowerhosting.com.