Hi, I’ve set up Postfix on my CentOS 7 VPS last week, serving mail for two domains.
I’m experiencing problems with some mail hosts marking my mail as spam. The mail that is coming from the primary domain (the one that the PTR of the servers IP points to) is sometimes marked as spam, while the mail from the second domain is constantly marked as spam. I’ve run both domains through all the tools at mxtoolbox.com and it reports that everything is OK. I’ve posted a lengthy explanation of the setup on Super User, which can be found here: https://superuser.com/questions/832749/some-mail-from-newly-setup-mailserver-flagged-spam-by-gmail The first domain (domain1.com) is over a year old, the second domain is roughly a week old. In addition to the SU post, I put my configuration up on pastern: http://pastebin.com/McGh8C6s For the sake of completeness I’ll state the domain names so anyone can take a look at the DNS config if need be: domain1.com = infinitesimal.nl domain2.com = isogram.nl As far as I can tell both domain names are not suspicious. The mail messages that I’m testing this with are regular messages, they are just older messages that I have in my sent messages box, so no suspicious language or anything like that. GMail complains that the message look similar to spam messages that where detected earlier, on the link provided in the SU post they list a couple of options, none of which seem to apply to my mails. The only thing that I can think of is that the IP has been used for sending spam in the past. However, I’m reluctant to create a new VPS to get a new IP, partly because Google mentions that changing IPs all the time is suspect as well. Any help would be greatly appreciated. -- - Tiemo
