Hello everyone!

My name is Nick. I have recently installed ISPConfig on a new DO droplet, with the following setup guide: https://www.howtoforge.com/tutorial/perfect-server-ubuntu-18.04-with-apache-php-myqsl-pureftpd-bind-postfix-doveot-and-ispconfig/

Everything on the server is working fine. I only have some trouble with the email. Sending mail is not a problem, I’ve tested it a lot with Mail-Tester and I get a very high score (plus by even getting a score it means sending a mail is not a problem)
But when I’m sending to for example a Gmail address, the mail gets put away in the SPAM folder. And even when sending a mail to an address with a spam filter “SpamExperts” I get a mail back with the message that it could not be sent to the recipient. I then actually get the following error: “550 Sender verify failed (in reply to RCPT TO command)”

Also the receiving part is not working properly. When I send an email to a mail address on my ISPConfig server I get the following error code back: 5.0.0.

Does someone know what I can do make both things work? I hope someone knows! Or maybe how I can better do email.

Thanks in advance!

• Nick van Kesteren