Outlook SPF DKIM DMARC Setup

I need SPF, DKIM and DMARC records configured so every message that leaves our Outlook-based Microsoft 365 domain passes authentication checks. The mailboxes are used mainly for internal communication,... (Budget: £750 - £1500 GBP, Jobs: Active Directory, DNS, Microsoft, Microsoft 365, Microsoft Exchange, Network Administration, System Administration, Technical Support)