text via email

It's not so much that Comcast offers this ability as a feature per se----------it doesn't.  But as a rule of thumb, most email and cell phone systems support the ability to send emails to a phone number and have it come out as a text message.  But the operative term here is "most".  Not all systems support it.  You may be having a problem if the domain you are sending to doesn't support the practice.  I just tried your experiment using my Comcast email, and it works OK for me.  I also tried with my Gmail and Vivaldi email accounts, and it works with those too.  Not much luck though with my Outlook.com account.  This is an older article I found a while back, but it should still be relevant---------------

Email to Text Messaging

And to add---------my cell phone service is with the MVNO Consumer Cellular (so AT&T system)  using @txt.att.net for the domain in my case.

@user_9j4921 

My guess is that the issue is probably at the receiving end.  Once your email shows up in the Sent folder, that's it.  I still haven't gotten a text message from the one I sent from the Outlook.com address, nor have I gotten any bounce or error message.  Here's an idea for an experiment--------------

Use the Comcast account to send an email to your own cell phone number as described in that link I posted.  Does it work OK that way?

I can send the email/text from my Gmail account but not from Comcast. Xfinity [Edited: Language]. I've had tons of problems both receiving and sending messages from different sites. They are never ever helpful.