David L.

Microsoft 365 & Exchange Expert | Email Security | Mail Flow | PowerShell Automation | L3 Support Building My Upwork Portfolio Currently growing my presence on Upwork, offering competitive rates while delivering enterprise-level support backed by 10+ years of real-world experience managing large-scale environments (100K+ users). I’m a Senior Messaging Engineer specialized in Microsoft 365 and Exchange (On-Prem & Online), focused on mail flow, email security, and advanced troubleshooting (L3). I help organizations keep their messaging environments secure, stable, and optimized. What I can help you with -Microsoft 365 / Exchange Exchange Online & Hybrid environments Mail flow troubleshooting (connectors, routing, delivery issues) Transport rules analysis and optimization Mailbox issues, outages, and escalations (L3 support) -Email Security Phishing & spam investigations Junk email analysis (why emails are classified as spam) Microsoft Defender / EOP troubleshooting Email authentication (SPF, DKIM, DMARC) -Automation (PowerShell) Task automation & reporting scripts Mail flow and message trace analysis Bulk operations and admin tasks Custom scripts for monitoring and troubleshooting -Migrations & Integrations Microsoft 365 migrations (cutover, hybrid, staged) Mailbox moves and post-migration validation Outlook / mobile / client connectivity support Why work with me 10+ years supporting enterprise messaging environments Real L3 experience handling critical issues and escalations Strong troubleshooting mindset (I don’t guess, I find root cause) Focused on security + stability + automation Tech Stack Microsoft 365 | Exchange Online | Exchange On-Prem Microsoft Defender | EOP | Cisco IronPort PowerShell | Microsoft Graph API Active Directory | Entra ID Outlook | Teams | SharePoint | OneDrive