Email Issue - Attachments from Verizon Messaging Application

Until just a few days ago I was able to send pictures (attachments) from my Verizon Android phone (message+ app) to my comcast email.  I get no error when sending but they messages no longer arrive nor are they returned.  Comcast insists it is a problem with Verizon msg app but I can send from that same app to my Gmail account and send that same msg to other phones.. only not to my Comcast email.  My wife attempted same from another messaging app on her Verizon phone and it failed as well.  Comcast is insisting it is a problem with Verizon, but all things point to Comcast from my assessment.  I was told by the Rep they did implement some new security code, but she didn't think that could be the issue for some reason.  I requested level 2 support and it was denied.. very frustrated at this point.  Any ideas or help is appreciated.