Is there a way to disable email-to-text?  I've recently starting to get a lot of SPAM text messages from email addresses.

Is there a way to disable email-to-text?  I've recently starting to get a lot of SPAM text messages from email addresses.  I can't seem to forward them to report them to abuse@att.net or 7726 (SPAM) from the SMS on my iPhone.  

iPhone's filter doesn't block the messages either, it just buckets them under "Unknown senders" which isn't really helpful.  I want to block them altogether. 

I've confirmed that they are coming from an email address to a group of phone numbers in random "group chat's" with my mobile number included. 

Any suggestions that don't require me changing my phone number are appreciated.  

Thanks!