As I know the email message sending process looks like this:
- The message is sent from sender's client to his server (say mail.com).
- The mail.com server redirects the message to recipients server (say gmail.com).
- Recipient's client connects to gmail.com and recieves new messages.
I'm interested in stage 2. I thought that the servers use SMTP protocol to make this negotiation. And gmail.com server should listen to 25 port to recieve a connection from mail.com and other servers.
But then I try to connect gmail.com (exactly, Google service) on port 25, the server is not responding...
Why? What's wrong?