Google for nonprofits –
Google offer to non-profit charities, free use of unlimited emails, all you need is a domain (i.e. lewishamscouts.org.uk) each email address comes with 30gb of drive storage. google also offer a few other free resources along with your sign up.
Microsoft 365 for nonprofits –
Get Microsoft 365 Business Premium for free for your group for up to 10 users.