Today a customer called with the Exchange 2019 mailflow issue.
Mailflow issue and D drive unavailable.
- Upon checking we found all services were running.
- This was the only exchange 2019 server on a windows 2016 active directory.
- Database was mounted.
- Outlook emails were stuck in the queue to Mailbox.
- OWA emails were going to the draft.
When I check the event view I got the following strange event log.
DnsErrorLog: Failed to create the log directory: D:\TransportRoles\Logs\Mailbox\DnsErrorLog\Submission\ because of the error: Access to the path ‘D:\TransportRoles’ is denied. Logs will not be generated until the problem is corrected.
- When you don’t have a D drive and you see this, you will be clueless.
- This was a new deployment and I asked the customer to give me a 100 GB D drive.
- We created D drive and Created TransportLogs Directory and we could see logs started coming.
- This above solution was part of the resolution but not a complete solution so emails were not flowing.
- Now when we did the nslookup, server name was unknown.
- Then we saw the error in the events and queue that DNS server 18.104.22.168 is unable to find the domain.
- Found customer has added public DNS in the TCP/IP settings of the exchange server.
Removed public DNS from exchange server and mail flow started working.
- Told the customer to add public dns in DNS forward of the Active Directory DNS.
Still I had the question in my mind that why default log files are going to the D drive.
So, I tweeted to Director of Product Marketing for Exchange Server and Exchange Online – Greg Taylor
Now I am waiting for Greg to Respond.