Failed to establish communication.

Question

Unable to establish contact; the recipient cannot receive the message. The following information was returned:

There was a problem sending your message. Please share the diagnostic code 504/1008 with your administrator to help them resolve the issue.

Answer 1

Thanks.

Can you see if changing the DNS helps?

1. Press Windows+R keys on the keyboard, or Right-click Start on the Taskbar and choose Run.

Type ncpa.cpl

Press Enter.

1. Right-click your device and select Properties.
2. Double click IPv4 options to open IPv4 properties.

4.Select the ""Use the following DNS servers"" radio box, and enter the following in the addresses.

1.1.1.1

1.1.2.2

1. Click OK and OK again.

Restart your computer.

Keep us posted and Good luck!

Answer 2

hello

1. operating system is windows
2. Outlook client : 1.2026.310.300
3. no firewall
4. Cannot establish a connection in Teams.

Answer 3

Hi Song,

The error indicates a network connectivity issue.

May I know which operating system you are on?

The Email client?

Any 3rd party firewall?

I’m eager to hear back and work together to find a solution.