The ramblings of a computer geek
The Microsoft Exchange Poison Queue is a little known queue on an on-premise Microsoft Exchange Server, maybe I’ve been lucky, but I’ve only seen emails end up here once in my time using Exchange Server which goes back to Exchange 5.5. However this week, we observed some messages going into the Poison Queue which were … Read more
During the preparation for a migration of the email service to Microsoft 365 Exchange Online, we were preparing a small test environment so we could step through what is required to faciltiate the links between Microsoft Active Directory, Microsoft Exchange on-premise and the Microsoft 365 cloud environment that includes Microsoft Exchange Online cloud hosted email. … Read more
Sometimes it can be handy to connect into an IMAP(s) server to verify it is working as expected, or to view emails via a command line interface. In this example I’m connecting to a Microsoft Exchange 2016 Server with IMAP enabled, specifically IMAPS, so running on port 993. Connect and Login Firstly we need to … Read more
We use SMTP on our Exchange Servers to provide authenticated SMTP email service for those who are using email clients which require SMTP to send email. We had an issue that following a certificate expiry that any SMTP connections to the server (that were attempting to use STARTTLS) would fail. For example: The issue was … Read more
We had an issue where a recent Windows update broke the Exchange Server, luckily booting into safe mode and removing it resolved the issue, however although the databases mounted okay, there was one that did not. We attempted the typical ESEUTIL steps because it was reporting “dirty shutdown”, and got the database back to a … Read more
You want to search your Microsoft Exchange message tracking logs to track an email, you can do this using a Powershell command (run from the Microsoft Exchange Powershell console), the below command will query all your Microsoft Exchange servers to find the tracking logs and then obtain all emails sent by the user “sender@domain.com” between … Read more
Emails are made up of a header and body, the body may be HTML or plain text, and any attachments are encoded within the body of the email for it to be sent. We have applied limits to our email infrastructure to reduce load, bandwidth, and disk space but also to protect recipients of our … Read more
We have a number of 2 node DAGs which provide our Microsoft Exchange 2016 service. Being a 2 node DAG a file share witness server is in place. We had a datacentre event that took out one of the nodes and the witness server, rendering the one of the DAGs unhealthy and a second in … Read more
We run a number of Microsoft Exchange 2016 server (yes I know we need to upgrade), these consist of four, two node DAGs with a pair of shared witness servers. For the purposes of this explanation however, we have a two node Microsoft Exchange 2016 DAG, with a single DAG Witness Server (File Share). Situation … Read more
In certain situations the Exchange DAG witness can become a problem, this can occur during an upgrade or can happen if there is a network interruption. Although the DAG will continue to operate the witness is considered failed, which can cause odd behaviour in a failover scenario, as there is no quorum available for the … Read more