SPF records: Hard Fail vs Soft Fail?

Question

When configuring my SFP records, should I be using a hard fail or a soft fail?  

Answer

While we cannot provide a definite answer, the following information will help you better understand the difference to make an educated decision on whether you should use a hard fail for SPF, or a soft fail for SPF.

The main difference between the two is pretty simple. Is it on the list? 

 A hard fail, for example, is going to look like this:

v=spf1 ip4 77.88.99.110 -all

 If mail is being sent from another server that's not the IP in the SPF, the receiving server will discard it. 

With a soft fail, this will get tagged as spam or suspicious. A soft fail would look like this:

v=spf1 ip4 77.88.99.110 ~all