I have a working configuration of ISPConfig 3.0.16 with mail server and website/virtual domain handling. All my domains are FQDN and the server send and received mails using webmail as well as IMAP/SMTP mail clients. My users have reported that their email is detected as spam to many of their recipients. The question is: How to make my server legit and known as NOT spam for every spam detection engine/website out there? Do I have to complete any kind of forms or subscribe to a specific organisation? Please help Thanks
No. 1) Make sure that your server is run on a static IP address. 2) Check if your server is blacklisted: http://www.mxtoolbox.com/ 3) Create SPF Records for your domains in DNS. 4) Make sure that the IP address of your server has a correct reverse dns record.
You can use this wizard to get an idea how your SPF record should look: http://old.openspf.org/wizard.html
A general purpose one is Record Type: TXT Domain: example.com. Data: v=spf1 a mx -all Priority: 0 added "a" : A records specify senders (without this some services, like yahoo, will automatically put you in spam).
