Dear friends,

When i tried to send mail to some other mail servers (only some), the receipient couldnt receive our mail. Their mail servers never block our address. Somehow i was told it could be possible that our mail address has been mistakenly categorized as SPAM mail by the RBL list or something. I am not quite sure if that is true, but what i know is that, our very own mail server use RBL list to filter spam, yet sometimes the RBL lists do mistakenly classified some of our clients mail address as SPAM, for that reason we cannot send to some of those clients. I am suspecting our mail address has also been mistakenly classified as SPAM by the RBL list, thats why they couldnt receive our mail...
Am i right or could be other problem? I am sure we each other server never block each other mail address, so the possibility that the mail has been blocked by our server's configuration (excluding RBL list) is out of question.

thanks for taking time helping,

regards
Y

Guessing you talked to some of them to know they are not getting your email. Ask them to view the mail the spam filter picked up and see if your email is in there. Then they can remove you from the spam list.
Problems such as this you need to talk to the intended receiptent to see what is really happening. If it is not in his spam email then it is not getting delivered as intended. Maybe your mail log would give you a clue of this.

Typically if you are blacklisted and you send mail to a server that gets rejected, eventually one of them will bounce the message back to you so you can check the error as to WHY it was rejected.. say 554 for instance..

You can also search the black lists to see if your servers IP is in their database.

Multi-RBL search This tool checks if ip or domain is listed in 25+ most popular RBLs
Another Multi-RBL search

Thanks guys,

I have checked with the website provided, my mail server ip is not badly listed in any of the RBL lists. weird....my mails to hotmail.com doesnt work, the log just say

Feb 7 08:10:39 mail postfix/smtp[13822]: 67A101F410D: to=<potatoatwork@hotmail.com>, relay=mx1.hotmail.com[65.54.245.8], delay=2, status=sent (250 <45C92165.5010901@shinyang.com.my> Queued mail for delivery)

which just seem pretty normal. I dont get any mail delivery error on my site too. weird...weird...

Thanks guys,

Regards
Y

Is your mail server hosted on a Static IP address ?
Some mail servers will not accept mail originating from Dynamic IP blocks used by ISP's. They may even silently drop mail from you without returning an error. Why return an error to a mail server that is probably just a machine that is infected by a spam mail virus ?

Hi farslayer,

Yes you are right. My mail server is running on static ip. Then i wonder why hotmail would drop me since i am static ip, not dynamic ip.
thanks

Well you could start by looking at the MSN postmaster site that explains how hotmail does blocking etc.. it's where the hotmail site tells you to go if you are having trouble sending mail to their servers..