MS. Exchange 2013 - You don't have permission to perform this action - Stuck in draft Folder OWA

My client said they cannot sent any E-mail and stuck in draft folder when they are using OWA. It's also give an error "You don't have permission to perform this action". They have troubleshoot for  whole day and found no idea to resolve it.

When I started looking at the issue, I went through series of basic transport troubleshooting steps for Exchange 2013 multirole server, such as checking all transport related services, possible back pressure issue, and state of all server components. Of course, there is nothing wrong with them.

Running out of ideas, I checked settings of send connector, just to make sure there is nothing out of ordinary. I see this in Send Connector properties,

There are no reason to use external DNS, For this environment, it's not needed as well. I've unthick the box but the problem still exists. 

I then run get-TransportService | fl *dns* to make sure that we don’t have any external DNS settings configured.

Ooops, there are external DNS Server setting. I run several NSLOOKUP test and found DNS server did not respon any queries. I think this is the problem cause.

To remove it, you have to run 

Set-TransportService -ExternalDNSAdapterEnabled $true -ExternalDNSServers $null

After restarting the transport service, all mails in the Draft folder are gone. Mail flow is restored!

Note :

If this action did not solve the issue, try to disable your Antivirus that installed on your Server. Sometimes, Antivirus blocked Microsoft Exchange services and will cause this issue.