- Mail Server Details
- Mail Issues Ticketing Form
- Email Settings
- How Email Works
- Advanced / Technical Details / Spam
- Outgoing Email Account Setup (SMTP Server)
- Attachment Problems?
- Changing your SMTP Port in Outlook Express
- Bounce Messages Explained
- 551 - User Not Local Errors
- Email Acceptable Use Policy
- Deleted Emails
- Spam FAQ
- Email Account Admin
The mail servers run POP3, IMAP
We recommend that you run POP3 so that you don't use up your disk quota's for email.
The mail server name for POP, SMTP is:
(The server name is the same for POP/SMTP/IMAP)
The account name is your full email address.
In order to send mail, you'll need to set server requires authentication in your mail client as detailed in the Email Settings pages.
If you don't do this, then you will not be able to send mail to anyone outside of your domain.
If you are experiencing problems sending mail - the server bounces it back to you immediately with a SPAM error, then you may have forgotten to change your SMTP port from 25 to 26.
(You are getting bounced because your internet has a "bad" ip address thats been used to send spam with at some point in the recent past)
Webmail is available for those who prefer to use web based clients - the webmail server runs on http://mail.computersolutions.cn
Make sure that your email settings are correct!
We've seen a small number of clients that call and tell us all their emails are bouncing, its all our fault, we're horrible people, and... all of these cases turned out to be that the clients hadn't had configured their email setup correctly, and they weren't authenticating with the mail server.
Please follow the setup instructions carefully. If you need additional help, you can make a support ticket at http://support.computersolutions.cn
All sites have 2 mail servers - a primary server, and a backup server.
The primary server for China based clients is mail.computersolutions.cn / 22.214.171.124 (located in Shanghai)
The secondary server for China based clients is mail.shanghaiguide.com / 126.96.36.199 (located in the USA)
USA based clients work in reverse - their primary server is the US one, and their secondary server is the China one.
How this works is as follows:
Joe Smith's mail server tries to send the primary server mail.
If Joe Smith's mail server has problems talking to the primary mail server, it will fallback to using the secondary mail server.
The secondary mail server will accept the mail, and queue it for the primary mail server.
When the primary mail server is contactable again, it will forward the mail to the primary server.
The primary mail server in Shanghai is backed up daily (every night local time) to two servers. A duplicate backup server located offsite, and a secondary server onsite (in Shanghai Telecom's hosting facility). In case of hardware or other failure, we can replace the primary mail server with the backup, and be back online within a few hours. In a worst case scenario, we can use the secondary backup to provide email functionality on a temporary basis until the main servers are replaced.
Spam checking (incoming)
We use spamassassin for incoming spam checking. We do a very limited amount of spam checking on our Shanghai servers - if we get more aggressive in our spam checks, we block too much legitimate mail from China based companies who send mail from ISP's used by spammers (Public.sta.net.cn, chinanet etc).
We currently (as of 26/Feb/2006) use the following RBL (Realtime Spam Block lists) in our US server.
Our Shanghai servers run the following lists as recommended by the government.
Even with the best lists we get complaints from clients saying that they can't send mail.
We estimate that approximately 40% of the broadband ip addresses handed out in Shanghai are listed in major spam lists.
We have recently implemented some receipt checks for incoming email - if we receive more than a certain amount of emails to non-existent users within a certain period, we block the sender address for a few minutes. Spammers usually send blanket emails to many fake names at a domain, so this works reasonably well. (It also puts less load on the servers as they can bounce spam before the virus and spam software gets to process it).
Any incoming mail that is 'definitely' spam gets prefixed with :SPAM:
While we try to please everyone, its a balancing act. Any confirmed mass spammers will be blocked from our server. If you have clients that cannot send you email, please have them check with their ISP if they are blocked on any of the major spam lists.
Clients can check spam listings at the DNS Stuff website.
We also use SPF in a limited way to check domain senders.
We are still evaluating the use of Domain Keys.
Domain Keys and SPF are ways to authenticate that email does in fact come from the domain that the mail allegedly comes from.
How does this help?
All legitimate mail from the server gets signed by SPF or DomainKeys.
Mail pretending to be from the server won\\\'t have a valid signature.
A virus sends you mail claiming to be from email@example.com
The mail server software checks the message to see if it is signed by the mail server. If it isn\\\'t signed then its not from firstname.lastname@example.org, so we can throw it away.
Spam checking (outgoing)
We have reverse DNS setup for 188.8.131.52 -> mail.computersolutions.cn
Reverse DNS is required for many domains now in order for them to accept incoming email.
There are a number of Spam listings that your recipients may use for filtering their incoming email.
You can check our mail server against many of these listings here -
Be aware that some spam listings are positive - these listings are ones that include *all* China Servers as spammers - we cannot get out of those. If this is a problem, tell your contacts that they are blocking all China email, which is silly.
Note that we do not have control of how other people filter / setup their mail servers.
If you are having problems contacting other people feel free to forward us the mail bounce message headers, and we can try to assist.
Occasionally our China clients will experience email and internet 'issues' with internet in general. This is unfortunately something that we have to live with in China.
Spam in general
Please do not abuse the facilities by sending unsolicited mail. Unsolicited Commercial Email (UCE) is highly frowned upon, and any clients sending mass 'Spam' will have their sites/email facilities shutdown on verification of spamming abuse, and be reported to the Chinese authorities in order to comply with Chinese law.
Spam reports should be sent to us via the contact form, or via RFC compliant methods.
The Ministry of Internet Information recently introduced some new spam laws, which requires mail server's to be registered with MII (similar to the recent ICP licencing).
We have setup a separate mail server for clients that send out regular mass mails to clients. Due to legal and other requirements mailing list services incur an additional fee.
Mailing lists are setup as opt-in to comply with China law.