Hi , our office just setup a mail server using Imail , we have a dsl-router as a firewall , we also open the port 25 & 110 for mail server , some mail server like Yahoo can't mail in our mail server , but some like Hotmail or MSN or other offical mail server can mail in , i have check our dns setting , nothing is wrong , but someone still not be able to mail in . my boss is very angry , but till now i still not find the problem , could you please help me to find out the problem , our domain : huofong.com.tw thank you !

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When I do a 'dig mx' on your domain it times out. Maybe that's what is happening for the domains who can't send mail to your domain? What mail daemon are you running? Is logging turned on? Have you checked the logs? Anything there relevant to this problem? Have you forwarded ports 25 and 110 to your internal mail server? (I would assume you have since some mail gets through, but you didn't specify so I have to ask) Can you successfully send mail to the domains (e.g. Yahoo) that you can't receive mail from? Have you seen the headers of any bounced messages sent to your domain? Any clues there? Can you post one of said headers?

yes ! we can mail out to yahoo or hinet ... & forward 25 110 to mail server our mail is : Imail when someone get reject mail is : posmater XXXX can someone tell me how to check if my dns is correct ? i just download dns expert pro 1.6 to check our dns server , his response is : the server din't reply . please give me more advice ! thanks !

"when someone get reject mail is : posmater XXXX" This is useless. At least give us the complete error message, if not the complete headers. "the server din't reply" This is a problem. If a remote mail server can't look up your MX record, it can't send mail to you. What DNS server are you using? Where is it situated? Behind your router? I think you don't have DNS configured correctly for your domain. "dig" shows this: huofong.com.tw. 2h43m50s IN NS mail.huofong.com.tw. huofong.com.tw. 2h43m50s IN NS huofong.com.tw. huofong.com.tw. 2h43m50s IN NS www.huofong.com.tw. Three name servers for your domain, but none of them respond to dns query. I suspect one or all of those should either be A or CNAME entries, rather than NS. Do you even have a valid NS entry, pointing at your real DNS server?