Don't use whois masking services, it effectively gives a third party ownership of the domain in question and most certainly does violate the ICANN rules about truthful and accurate registration information.
When the whois protection service is provided by the registrar you used to register the domain, how is that third party ownership? They already have a lot of control over the domain.
I don't know about ICANN rules on the matter, however I think they would have pressured registrars to stop offering such services, if that was the case.
If you have further information/links on the subject, please elaborate.
TL;DR: you can do it, but understand the risks you are taking. The whois record is the authoritative record of domain ownership, if your name (or company name) isn't on it, then if there is a dispute, you lose.
I can tell you for a fact that I receive a lot less email spam at the email address I use for whois, because Namecheap changes the address (which forwards to mine) listed every other day. Also I don't get any snail mail junk, although this was never a big issue.