One of you is right. Which one?
1. A system for sending and receiving email.
You can probably find prior art for that.
2. Claim 1 where the email is sent over a TCP/IP network
And probably you can find prior art for that.
3. Claim 2 where the network is wireless
NTP won over $1 Billion for filing a patent with a claim about this serious, mostly from Blackberry.
Now you can continue like this indefinitely. That's why every time there's a new system, there are thousands of new patents that can be issued. Email on a phone, email over multipath TCP, email with a touchscreen, email with MIME messages, email with MIME messages on a touchscreen, &c. Each of those is considered valid to patent by the PTO. Then instead of email, try playing MP3s, or word processing, or online backup. You quickly arrive at a thicket of a million valid software patents covering everything you might ever want to program many times over.