Messaging & email architecture
Mail is the system users notice first when it breaks and the one attackers reach for first when it works. It is the area I know deepest.
- Exchange Online and Exchange hybrid topology, including coexistence during long-running migrations.
- Mail flow design: connectors, transport rules, routing decisions, and tracing a message end to end when the answer is not obvious.
- Authentication and anti-spoofing โ SPF, DKIM and DMARC taken from monitoring-only through to enforcement without breaking legitimate senders.
- Deliverability and reputation work, plus the tenant-side controls in Exchange Online Protection and Defender for Office 365.
- Exchange Online
- Exchange hybrid
- SPF / DKIM / DMARC
- EOP
- Defender for O365