I have used the issue "unified emai" addresses because I can't think of any other way to describe the problem.

Daughter in law gets an android system phone and the Verizon store staff help set her email up on the phone. She liked the idea of getting all her email on one screen on the phone so they set it up. She then has the new required gmail account and an old Charter email account. On her phone she sees all emails to both accounts in one folder. So far so good.

Now the weird part. She noticies no difference when she goes to her Charter eamil account on her home computer. She can read and respond to her Charter emails either on the computer or on her phone. But I send her an email if an attached .exe file to set up remote access to her computer. I get back a dameon notice that gmail has stripped the file from that email that was sent to her gmail account. But I didn't send it to her gmail address.... I sent it to her Charter email address. The email then does arrive at her Charter account missing the file. (Note:Gmail terms block .exe files from being recieved but Charter does not. I know because I sent the same file to another Charter address and it worked fine.) So why is gmail intercepting her Charter email and then appling gmails rules to it before realying it to her Charter account?

So the question is: What did the Verizon store staff do that has all Charter email sent to her go through the gmail server first before being relayed to Charter?

Second question is: Is that the only way a unified email folder will work (IE sending all emails first to gmail and then relaying the email to Charter's email server)?

I know other methods to get her the file. I am more interested in how and why the phone Android unnified email setup sends all Charter (and I assume other linked email addresses) first to gmail and then relays it to the other address.