Around 2013, I exclusively used Google Voice. It seemed silly that telecom companies would only offer phone plans that charged separately for data, voice, and messaging or even just messaging and voice (minutes) when it could all just be sent over data (see previous post about creating a data-only phone plan). The only problem I had with it was that Google Voice didn't support MMS (although I'm happy to say that, as of 2018, they do now).
But could there be a way to force it? I gave it a shot. Overall, it was pretty hacked together, but I was able to receive a photo at my phone, and I could send a photo to a phone from an email client on my phone. This is how it worked: I used an email server (that comes with Linux by default) and wrote a script to route MMS messages across the email account, spoofing the phone number so that responses to the text would be sent back to the phone. After all, an MMS or SMS is basically just an email protocol. Look at the structure of an SMS address:
5558675309@txt.att.net
The first part is your phone number, and the part after the @ is the name of the phone company's SMS server (in this case, AT&T, but you can google the name of yours).
One you know your phone's SMS address, you can use it as part of a call to the email program. In the command line, it's just called mail:
echo "hey girl hey" | mail -v 5551118888@txt.att.net -F 5558675309@txt.att.net -f ConanOBrien
This will send mail to the 111-8888 number, and make it look like it was sent from the 867-5309 number (or "ConanOBrien"). Check the man page for "mail" for more information. Note that if you are testing by using an email address as a target, some email servers (such as an organization using gmail) will blacklist spoofed messages, because that obviously comes off as pretty sketchy. Additionally, don't expect too much privacy if you try to go through a temporary email service, especially one with a public facing inbox like Mailinator. If the user has a way to view the traffic it could show a lot of private details like the host name of your local machine:
Received: from [MY LOCAL DOMAIN] ([MY HOSTNAME] [MY IP])
by [MAILSPAMMER SITE] with SMTP (Postfix)
for [INBOX NAME]@mailinator.com;
Sat, 04 Jan 2014 10:26:39 -0800 (PST)
Received: by [MYCOMPUTER LOCAL DOMAIN] (Postfix, from userid 123)
id 49C1AEEAAEE; Sat, 4 Jan 2014 13:39:14 -0500 (EST)
To: [MAILSPAMMER SITE]
Subject: subject
Date: Sat, 4 Jan 2014 13:39:14 -0500 (EST)
From: [MYPHONENUMBER]@[PROTOCOL].[CARRIER DOMAIN GATEWAY] ([MYPHONENUMBER]@[PROTOCOL].[CARRIER DOMAIN GATEWAY])
Sender: [MYPHONENUMBER]@[PROTOCOL].[CARRIER DOMAIN GATEWAY]
x-connecting-ip: [MY IP]
x-received-time: 1782851999324
MIME-Version: 1.0
Yikes. Anyway, during this course of this project, I had to attach a photo to an SMS message. One way caused problems for the target (it crashed an iPhone 4):
uuencode little_kitten.JPG little_kitten.JPG | mail -s "Can you see an adorable cat (mms)?" 55511188888@txt.att.net -F "Burninator" -r "5558675309@txt.att.net"
(or possibly MMS.att.net instead of TXT.att.net)
Oops... who knew such an adorable cat picture could crash your phone. It was a text bomb. This sent a lot of bizarre characters to the phone, and I'm honestly not sure if it was because of the amount of data that was being interpreted as text (instead of an image) or if one of those unencoded characters was the cause of the crash (perhaps similar to a problem from last month where a unicode symbol was crashing iPhones).
