[Creativity]

While I was looking through marblehost.com web site I explored that this company offers SPF Protection within their shared hosting plans.

What does SPF Protection mean? Do you think that their pricing is affordable?

[Iron-man]

Well, SPF stands for Sender Policy Framework and is an extension of SMTP that stops email spammers from forging the "From" fields in an email. If the email comes from a domain that is not authorized, the DNS server will not forward the email to the expected destination.
The prices for Marblehost.com plans look to be affordable and I think that you will make good hosting experience while dealing with them.

[Launch]

Marblehost.com web hosting plans look attractive for me as there are many features and bonuses included into them.
Not all companies offer SPF Protection, and I can add that I have read many good reviews about them - many people appreciate them.

[MikeTrike]

It's basically adding a SPF record to your domain, it takes about 5 seconds. It can also be automated on account creation.

Examples:
v=spf1 mx ~all
v=spf1 a mx ip4:12.34.56.78 mx:domain.net ~all

Basically it tells the recipient server what servers are authorized to send mail for a given domain. If a server sending email for domain.net is coming from a server not listed in the SPF record it will likely be rejected. Many mail servers also weigh not having an SPF record highly and you may end up in spam folders, etc.

[BarKeeper]

Marblehost.com looks to be good and reliable web hosting provider, so I suggest you not to waste your time and contact them directly to get all things cleared with them.