SMTP + Auto Switch + Agent Connections

[admin]

It is a true case in Hong Kong. Our broadband provider and email provider (in China) not allow us to send self email, ie alfee@sina.net is not allowed to send to alfee@sina.net. But when my laptop used in China and send email, this test is allowed.

To fix this problem, we set up a flexible routing, to bypass provider detection.

Hong Kong Side Settings:
1. Start up Magic Router in Hong Kong server, go to Network page.
. listen port = 25
. To port = 2025, to host = 192.168.1.10 (same computer).

2. Click Advanced button next to "To Host", enable auto switch, input spare server definition
. 192.168.1.10,2026
. Why we use spare server at the same time, because of backup. Once 2025 is down, 2026 will take place.
. Press Start(0) button.

3. Set up listener client on the same Magic Router
. Go to Agent page, in put the following setting
. Port forward definition: 0.0.0.0,2025,gzsmtp.sina.net,25,TCP
. 2025 is for 25 port routing, final server is gzsmtp.sina.net:25
. Input user name USER1 and password on listener client
. Input server port = 2222, ip = 222.125.44.88 in client common, where 222.125.44.88 is the ip of forwarder located in China office.
. Press Start(2) button.

4. Set up spare server in case of first China Forwarder down.
. Start up another Magic Router in the same server, go to agent page,
. Input port forward definition as: 0.0.0.0,2026,gzsmtp.sina.net,25,TCP
. Input user name USER2 and password on listener client
. Input server port = 2222, ip = 192.168.1.20 in client common, where 192.168.1.20 is the ip of agent server located in Hong Kong office.
. Press Start(2) button.

China Side 1 Settings:
1. Start up Magic Router in the China server, go to agent page.
. Input local port = 2222 in agent server.
. Press Start(1) button.
. Start up forwarder on the same Magic Router,
. Input user name USER1 and password on forwarder client.
. Input server port = 2222, ip = 192.168.2.10 in client common, where 192.168.2.10 is the ip of the same computer.
. Press Start(3) button.

China Side 2 Settings:
1. Start up Magic Router in the China server 2, go to agent page.
. Start up forwarder,
. Input user name USER2 and password on forwarder client
. Input server port = 2222, ip = 203.85.210.22 in client common, where 203.85.210.22 is the public ip of the Hong Kong Agent Server computer.
. Press Start(3) button.

We have used 2 Agent Server in the above setting. 1 is in China, 1 is in Hong Kong office. Use of the second agent server is because of no public ip of second forwarder in China.

The above connection is not only for "self" email sending, but for normal SMTP routing. 192.168.1.10:25 is not only accepting local office email, but simulate a China side server. Broadband or email provider do not know what we are doing. Therefore they cannot detect our email routing.