There is a huge difference between emailhosting.com and emailhostings.com. "email hosting" got over 5 millions returns on Google. "email hostings" got under a thousand.
emailhosts.com would work much better as a plural (or a portal). As it is, emailhostings.com is close, but no cigar. However, it still deserves a range of $xx to low $xxx if someone has a need for the plural syntax. Good luck!