I know this is a subject that has been well covered here and throughout the web, so I am not asking for a list of carrier emails, however my question is how to send a text without knowing the users carrier and preferably without going through a third party. The only solution that I thought of would be send out to all carriers. I would only be sending to US carriers, however would a large number of failed emails slow the mail server at all or cause any other problems? Any advice on this solution or thoughts of others would be great.