Migrate legacy EWS scripts to Microsoft Graph in 2026: three Graph surfaces, OAuth + app permissions, RBAC for Apps, EWS to Graph cookbook + side-by-side examples.

2026 Exchange Online playbook: HVE GA, SMTP AUTH Basic Auth retirement timeline, DMARC enforcement, connector architecture, transport rules and Defender for Office 365 baseline.

SMTP AUTH Basic Authentication in Exchange Online is being phased out. This guide shows how to find every sender still using it, choose the right migration path, and move to OAuth, SMTP Relay, HVE, or Graph API before it breaks production.

Exchange Online High Volume Email (HVE) helps organisations send large volumes of internal notifications without hitting standard mailbox limits. This article explains how to configure HVE correctly, avoid common authentication and Conditional Access issues, and keep mail flow under control.