Dear Marco,

i found the solution, it is due to missing user right to let the frontend transport and hubtransport to read the mailbox/account created by SolidCP.

after add the security rights to the account/mailbox email able to receive. 

authenticated Users

Read web Information = Allow

Read Public Information = Allow

Read General Information = Allow

I checked my own environment and it seems those are enabled on newly created mailboxes for me.

Is there any hardening done or non-default active directory aspects that could of influenced why it's different for your environment?

I just checked my config and these permissions are in place, the new accounts cannot receive mail still. Have removed and recreated multiple times with the same result. I checked in to AD config and all logs are clear dcdiag is clean, no DNS errors, I am running in to a wall.

Hello Marco,

I installed a new 2019 Standard with Exchange 2019 CU1 and Solid CP 1.4.2.

And got the same error.

Users are unable to get e-mails from outside the server.

If I move the user from the OU that SolidCP created to Users Exchange Customers (the OU that it upper then the OU that soildCP created) it is getting e-mails.

I checked what Gen Jacks wrote and the security settings that she wrote are set.

What else I can check and who I can fix it ?

Thank you

Eran

Hello Eran Agmon

SolidCP ver1.4.2 doesn't support exchange 2019.

Try again with v1.4.3 or use exchange 2016