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 […]
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. […]
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 […]
More...
It used to be easy to flush the cache, but recent changes to the DNS Client on Microsoft Windows 10 (and 11) have made this more difficult, you used to be able to run an “ipconfig /flushdns” or failing that restart the “DNS Client” service, but these don’t appear to work any longer. However you […]
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 […]
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 […]
More...We had an issue where our RODCs suddenly stopped authenticating users and also would not allow administrators to logon via RDP or locally via the console giving this message: “there are currently no logon servers available to service the logon request” Any downstream services that were trying to authenticate via LDAP or LDAPS also failed […]
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 […]
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 […]
More...The lowly Format command provides some simple, yet fairly effective data destruction for hard disks that you have on your machine. Although this technique may not be suitably effective for all data destruction requirements, it is fairly thorough in the destruction of data on a disk; such as one you wish to reuse for another […]
More...