Exchange 2010 to Microsoft 365 Migration – Recommended Approach and Tools

direct migration from EX 2010 to EXO by hybridization is impossible

I think even from 2013 to EXO isn´t possible anymore

also, inbound traffic and DNS records often needs some adjustments to ensure this....

independent from that, question is if you want to sync your users by Entra Connect. if you don´t, it must be ensured all EXO user properties match their local attributes and there is no adjustments whilst your migration that are not made visible

this is a requirement for both possible options to migrate the data without extra hops:

direct migration can be possible by PST Export (not a recommended way of doing this). PST Files can be directly imported in EXO, but take a lot of time and come with several downsides

otherwise migration by tool is possible.. server based solution that runs in the same network as your Exchange might be the least effort.

But still you need to configure all things in EXO that you need. 

recommendation would be to first cleanup, then ensure proper UPN and user attributes, then setup new exchange with new DNS records and ensure WWW inbound, then hybridization, then migrate it to a new Exchange environment first. be careful with autodiscover resolution of the new server dependant on your office version. keep in mind autodiscover resolution order differs in each office version.

Also ensure, GPOs are matching with an eye on your office version

For EXO mailbox you need new Office version as well (which you might also need to roll out first)

Also keep in mind the new Office version will resolve EXO environment first, independent from autodiscover record.