about email server at china

our office have a mail server and web server which at china.

recenlty, we cann't connect to the server from HK to china server, but if connect from china -> china without problem

We used this server over 4 year, but no any problem...

anyone know what we need to do now? as checked HK/china isp, they said no any problem for the connection.

By the way, I can ping/ tracert the email server, but if I use telnet domain 443 or 80, it will fail..., Mean I can reach the server, but cannot reach the Port 443/ 80.
But if do the same at other china city, which is ok to telnet.
any idea?

smtp port 25?? relay ?

via HKEPC Reader for Android


it a exchange server, seem port 25 is ok

But if access by HK webmail (443) or outlook port, alway fail in this week.....


what is your email is use pop3 or imap??/


it is exchange..not pop3 or Imap

I just add a Exchange account in my outlook, input user name + password, exchange will auto setup.....


You IP being filtered by Great Firewall of China (GFC). Try changing the public IP address and the telnet to the port should work for a while. Long term solution is to have VPN tunnel to avoid open those ports to public.


本帖最後由 kitnba 於 2015-8-29 15:35 編輯

oh..we are using FIXIP at hk....can apply something to china to whitlist my IP?

as I know , china will block other country  website.

But now maybe blocked my HK IP ,so I cannot  access my Email server....

But i still can Ping/trancert/VNC...


本帖最後由 evantkh 於 2015-8-29 16:40 編輯

Have you registered for ICP license?


本帖最後由 kitnba 於 2015-8-29 18:43 編輯
Have you registered for ICP license?
evantkh 發表於 2015-8-29 16:34

    any more info? the server is setup by Our China Team....
By the way, the domain.com which is hosted in HK ISP, but the MX record is point to my CHina Exchange server.
SO, we need apply this?

I think they didn't apply anything


any more info? the server is setup by Our China Team....
By the way, the domain.com which is  ...
kitnba 發表於 2015-8-29 18:37

You need an ICP license if your HTTP/HTTPS portal is running in China.
However, it seems that your website is running in Hong Kong.

I think you can set up a site-to-site VPN.