I am configuring a VPS on Windows Server 2012 R2 using MailEnable as email server.
As the port 25 is blocked by ISP so I use port 587 instead.
When configuring on email client Outlook or ThunderBird, it all passed test and I am able to receive test message from outlook.
Below is my Outlook setting:
However, I am not being able to receive any test email when I try to send from gmail or hotmail, etc.
I checked the server firewall and port 25 is open.
Can anyone please help with this, thank you.
Best Answer
TCP port 587 is for mail submission from clients. Receiving email from other mail servers requires TCP port 25. You'll need to either move your server elsewhere or get your ISP to open that port.
You will also want to un-check the "authentication required" option, as remote mail servers have no way of authenticating themselves to your server.