No. We don't offer any guarantee. But we get the carrier-lookup information from the same source that the wireless carriers themselves use for routing their customers' text messages. So the carrier data should be extremely accurate and up-to-date.

As far as the email gateway addresses we provide, we do our best to keep these up to date. However, there are some carriers we do not have the information for. In fact, a few of the smaller carriers don't even offer an email-to-SMS gateway address.