Microsoft Exchange Poison Queue

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

Cisco ASA Firewall (5506-X) with BT Openreach FTTP Internet (Plus.net)

Was working recently with some colleagues on their coursework, where they had a need to configure a Cisco ASA Firewall to prepare a network topology that met certain criteria. They were using Cisco Packet Tracer, but were having a problem creating sub-interfaces (for each VLAN), it seemed that Cisco Packet Tracer (or the current version … Read more

Certificate Warning During or After a New Exchange Server Installation

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