Interesting little bit of info:
I sometimes try and use <phone#>@vtext.com to test if txt messaging is really work or not.
I just did a test and got a return notice:
When trying to deliver your message, the mail server xxx.xxx.com encountered problems with the following addresses. Still trying, no action required!
For <phone#@vtext.com>, Open (66.174.3.30) Error 1sec (421 Server too busy, please try back later).
So from this message, it appears that maybe Verizon is not accounting for all the messaging traffic and is still having server troubles?