Hello, I just installed ISPconfig 3 with Dovecot, SpamAssasin and Postfix. I created site and so on, created email and now I have problem. I receive no emails, even when I can send emails. I can't even accept emails from google but I can send emails with no problem. When I used mailtester ninja an email checker for verifying it has told me " Status: Invalid email address, the mailbox for the email address does not exist. Status code: MailboxDoesNotExist" In logs is nothing about even that, the sender reached destination server where is email domain created. I tested it with mxtoolbox.com and it has right NS servers and MX servers too.
The right way to test it is this: Login to webmail on your ISPConfig server with the email address and password of the mailbox you created in ISPConfig. Then send an email to the mailbox that you used for logging into webmail. Does the email arrive in the mailbox after a few seconds? If yes, then your ISPConfig setup is working fine and the problem is outside of your ISPConfig system.
If the above works, your issue is likely caused by your ISP blocking port 25 incoming. This is very common if you try to run your server at home or in the office or if you run it at a cloud provider that has not explicitly allowed running email systems in its cloud.
