Possible to send sms over seas via email gateway?

[nite_monkey]

So I live in the USA, and have a phone with Verizon. My sister's husband is stationed at the air force base in the UK, and she has a phone with Vodafone.
Would it be possible for me to add 0n(at)vodafone(dot)net to my phone as a contact, and her add n(at)vtext(dot)com to her phone as a contact, and we be able to text each other back and forth without getting hammered with long distance messaging fees?

[4wd]

Shouldn't be a problem, however it would pay to check whether:
a) it's completely free,
b) it's counted as part of the recipients "included" free SMS quota, (if on a plan), or
c) the recipient is charged for the SMS.

[nite_monkey]

Sounds like it might work then.
I know for me at least, it doesn't cost extra. It's just counted as a regular message even if its an email address. I'll have to ask my sister, but I would assume she also has unlimited texting (back in high school and college, she would pretty much text from the second she woke up, to the second she went to bed) and unless vodafone is different from AT&T or Verizon, it probably won't cost extra to send a message to an email address.