I have delivered an email twice, all failed, then tried webmail, no failure notice received. So I contacted my mail service provider (a hosting company), The reply I got is as follows:
added the following CNAME
Then they added for me. Now I can't access via outlook, can't access via webmail. Even the website is not there. They said they need to create another "A" record for me.
Can Anyone kindly tell me whether all these make sense? They explained to me about "DNS propagation", didn't explain why it causes DNS propagation.