Microsoft 365 & Dynamics Multi-Domain Setup

I need an experienced Microsoft 365 professional to design and deploy a single-tenant environment that cleanly hosts several companies, each on its own domain. The core focus is to keep data, chats, documents, and ERP records securely separated while still letting me manage everything from one console.

Our Microsoft 365 stack
• Exchange – multiple domains, SPF/DKIM/DMARC, transport rules, address policies
• Teams – messaging, audio/video meetings, file collaboration; domain-based policies, guest settings, and retention
• SharePoint – dedicated sites per company, permissions and DLP

On the business side I want Dynamics 365 ERP modules—HR, Sales, Accounting—provisioned and ready for daily operation. That includes security roles, business units that mirror the domains, basic workflows, and tight integration with Outlook and Teams.

Deliverables
• Architecture plan outlining domain segregation, licensing model, conditional access, and naming conventions
• Step-by-step implementation of Exchange, Teams, and SharePoint with documented policies
• Deployment of Dynamics 365 HR, Sales, and Accounting modules with sample data, role-based access, and simple approval workflows
• Admin runbook and end-user quick-start guides
• Knowledge-transfer session so my in-house IT team understands ongoing maintenance

Acceptance criteria
• Users from one company cannot view or share content with another unless explicitly granted
• Mail flow, Teams calls, and SharePoint permissions function flawlessly for each domain
• Dynamics data respects security roles and business units we define
• Clear documentation delivered in Word or PDF

If you have completed similar multi-domain Microsoft 365 and Dynamics rollouts, please outline your approach and estimated timeline so we can get started.