send mail with attachment file that put on other Ip address or server

Dear

I am facing two scenario with some small issues.

If you are getting properly send me your suggestions..

èHow we can upload file from one network to another network

Suppose my application is running on IP1 and on this application, file upload is there but I have to upload file at IP2

èsame thing my application is working on IP1 and at this application I provide one functionality of send mail with attachment but problem is that I have to attached file from IP2 that saved  in previous stage.