I have a mail server with postfix(no TLS), it's been working for 2 months but recently we've discovered that some ISPs are seeing our emails as spam. When we look at the logs, the emails are sent ok but never actually reach their destinators. I don't want to get in the specifics but in a general sense, what would be the reasons mail coming from my mail server is seen as spam by some spam filters?
Dynamic Ip, incorrect Rdns are a couple reasons your servers mail could be seen as spam. You can also check to see if your ip is listed on any blacklist. http://www.mxtoolbox.com/blacklists.aspx
Servers with Dynamic IP are blocked by servers like hotmail. I am experiencing this problem as I have a dynamic IP and I am planning to purchase a static one to get around this. However, if you have a static IP, then you may need to try this wizard to get info on how to get your mails through to hotmail. http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/ Hope this helps!
Thanks, we have a static IP but the only problems we've had is with the biggest ISP in Quebec and 1 or 2 hosting companies in the US. I'm pretty sure that if we correct the PTR record everything will be fine...I think
