Hi This isn't related directly postfix but i could not find true platform to ask. I believe your knowledge is far better than mine and i need little help.
We are having difficulties while delivering mails to Microsoft's domains like hotmail and outlook. I've checked over and over again my settings on qmail and dns. Also couple of days ago i raised a ticket on hotmail's support page but no response yet. The real problem is that mails send from our mail server are delivered in spam/junk folder instead of inbox. There are ten domains on this mx and they all have same problem. This leads me to think that problem related my ip or ip subnet. Yes, there are many ip adresses listing in famous blacklists on my subnet. By the way, this problem only occours on Microsoft's domains. Mail server have valid ptr, spf, dkim and dmarc records. Also spf and dmarc records are strict and doesn't contain relaxed or soft fail parts. I know it is very common issue and every week someone ask guidance like me. I'm also subscribed this mail list and saw couple of mails that mentioned problems like mine. But i did not finish my research. Are there any others dealing Microsoft's spam mechanism ? If yes, please tell me what did you do about that ? On some sort of links Microsoft suggests to follow Return Path's certification program. But i did not deeply look up yet. After a quick scan, i found prices section and they demands subscriptions fee. I 've heard somethings about that Microsoft checks sender ip networks (whole ip subnet belongs to isp) as well as ip address and uses this information on delivery occurs. But no evidence found yet. Is that a rumor or a fact ?
