I installed cloudflare 2 days ago for my client. Emails are working fine if coming from out of their own domain. Their webforms stopped working(Because they had own domain email address as a receiver, Which is now changed to gmail/Working now) Company employees are able to email each using web outlook(office365) only but they can’t do it using desktop app(Like Live mail), They can email to others who are not on their own company’s domain using Live mail
Your post is a bit confusing.
Most email settings would not be changed during a move to Cloudflare DNS.
Was your client using Office 365 before you changed the nameservers? If you lookup the MX record for the domain, does it look like this:
Have you confirmed that all DNS records were migrated, and that any email related records are