I am using ispconfig with sendgrid as smtp, I can send mails but I cannot receive. Check my DNS and they respond well, there is something that is blocking me to receive, in the logs it does not show anything that comes from the internet. How can I see if you are rejecting emails that enter my postfix? Regards
I do not really get your setup. You are sending mail via sendgrip, which is an external sender, correct? You want to receive mails via your local (on your server) install of postfix? If they enter postfix, it should be logged in /var/log/mail.log If there us nothing, then a) postfix is not running or b) something is blocking it before it enters postfix. Could be your firewall, if you have one. Could also be that you have not correctly set up your MX records for the domain.
When you are using SendGrid, then your ISP probably blocks email ports and does not allow direct sending? Contact the ISP that provides the internet access for your server and ask them if they block port 25.
