register at link
generate creadential(API key and secret key) details and get SMTP server and port at link
manage domain and sender at link
at link click tab SPF and DKIM authentication
to setup SPF and DKIM
get SPF detail and DomainKeys/DKIM detail then go to Cloudflare to add new DNS record for both SPF and DomainKeys/DKIM, refer link
test SMTP server at link
notes: username is API key and password is secret key