Mail is not working properly on fresh ISPConfig install

Hello everyone!

My name is Nick. I have recently installed ISPConfig on a new DO droplet, with the following setup guide:

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

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According to the error I believe that this could be due to the content of your email, what are the tips that the Mail Tester site gives you?

What you could do is add an SPF record to your domain name and also a DKIM record to increase the delivery of your emails.

Also make sure to white-list the email that you are sending from via your Gmail account.