I having a 12.04 Ubuntu with LAMP stack droplet and have configured iRedMail which comes with Postfix. After the setup I am able to receive mails and also send mails to gmail and yahoo mail servers. However, with the other domains its giving me the following error : Diagnostic-Code: smtp; 550-Verification failed for email@example.com 550-No Such User Here 550 Sender verify failed
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