Signature and return address help..

[Kayoss]

I have a Sprint Diamond, flashed to Cricket, running MightyRom 4.4. I want to know if there is a way to edit the signature and return address when sending a text message to an email address. Currently, the recipient will receive an email with the return address of xxxxxxxxxx@sms.mycricket.com and a signature that reads, *sent from a Cricket mobile device* I can add a signature but that doesn't change the Cricket signature.