I use the same server for sending my emails and web hosting. I send user registration and support forum mails from my server and occasional marketing mails or newsletters.
I read on a CloudFlare blog that if I use the same server for email and web hosting the headers of the mails sent will contain my IP which will make me exposed to DDos attacks but my hosting provider says that there is no such threat with IP's in mail headers.
I am confused if it's okay to use the same server for both web and mail and does having my server's IP in the mail header really does increase the risk of DDos.