Hi all I am using a server centos 7 and i have installed ispconfig without any error my problem is that i can receive emails but i can't sent i have tried with gmail and outlook com and it gives me an error but when i send to yahoo i can send them email but it goes to the spam folder. my ip is not blacklisted i already checked i know that is something with reverse dns but that i don't know how to fix it or is problem with dkim if someone would help me i would really appreciate. This is the mail system at host ............. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <frrokuylli@gmail. com>: host gmail-smtp-in.l.google. com[74.125.133.26] said: 550-5.7.1 [xx.xx.xx.xx] The IP you're using to send mail is not authorized to 550-5.7.1 send email directly to our servers. Please use the SMTP relay at your 550-5.7.1 service provider instead. Learn more at 550 5.7.1 https: // suppor t.google. com/mail /?p = NotAuthorizedError m24si10752357wrm.2 49 - gsmtp (in reply to end of DATA command)
Is the server hosted at home or in office? it seems as if your IP is in a network that is marked as dialup / cable / dsl IP addresses and not as a datacenter IP. To prevent spam, all IP addresses of "end user" internet access systems are on blacklists, so you can only send trough the relay server of your ISP then or another internet relay host.
