First time Install and Config Exchange Server 2019: Some questions

Copper Contributor

Hello everyone,

I am pretty new to Exchange Server 2019 so I decide to give it a try from installation to final config

I have processed the following:

1/ Register public domain ( and for example), setting up A record and MX record, pointing to our public IP: All good, using show DNS record publised and all.

2/ Install Exchange Server 2019 on Windows Server 2019 - Standard edition: All latest updates done

3/ Config Accepted Domain, Send and Receive connector

4/ Create 2 mail receipients so far: Administrator and User1

5/ Sending and Replying a Test mail between the Administrator and User1 successfully

6/ From outside of LAN, I can access OWA and ECP, check email via web-page browser successfully


But so far, I cannot send nor receive any outside (Internet) email... I tried to send a test email from User1 to a google mail or other public emails, it said there is a delayed, with error message for example as per the following:


"Server at ( returned '451 4.4.397 Error communicating with target host. -> 421 4.2.1 Unable to connect -> SocketTimedout: Socket error code 10060'


Am I missing some steps along the above?

Thank you again for your patience and support

Kind regards

3 Replies

While reading it could be an issue on Google's side. Have you tried to send to a domain? Or have you tried port 2525?

OK, so I learn that my ISP has blocked the port SMTP 25 which is used by most mail server to send/receive mail from/to outside mailer. I have asked the ISP to release the port however, they said it's blocked by the spam policy and not an option to open it, unless it's a registered commercial IP
What are the option that I have in this scenario? Using different port or anyway to bypass the port 25?
Thank you
You can't bypass it. You have to have the port free, the other thing you can do is to use a smart host service. Have you pointed you MX records to your Firewall? Do you have any send connectors configured?