Moving from MS365 provided by Ionos(1and1) to Zoho Mail

Moving from MS365 provided by Ionos(1and1) to Zoho Mail

Hi

Hoping for some advice.  I am currently using 1and1 for my domain hosting and have MS365 through them.  I would like to migrate my email from MS365 to Zoho Mail (but keep my domain hosted on 1and1 platform).

I've read the instructions about creating the MX records & SPF files, I've also read the instructions about migrating from MS365 to Zoho Mail.

My question is what do I do first...do I update my records on my domain and then migrate or can I just migrate to Zoho.

If I change the current records then mail will stop coming in until migration is complete...if I migrate then I dont think the mails will deliver or be allowed to send until I update the records. 

I am also concerned that I want to make sure Zoho Mail is 100% right for me before closing my MS365 subscription and by changing the MX & SPF records this will stop emails being sent via my MS365 account?

Any advice would be greatly appreciated!

Thanks