Domain Registry of America (DROA.com) used to send confusing emails and hardcopy letters to our customers (and almost all other domain owners!), claiming that users need to renew their domains with dora.com!
Please ignore these emails--it's a scam. If you registered your domain(s) with 2MHost.com, then the only way to renew the domain is through 2MHost.com.
Another website to be wary of is DomainRenewalGroup.com--it is also a scam site that's simply trying to get your money.