Subdomains on CloudFlare are marked with an orange cloud. Subdomains not on CloudFlare are marked with a gray cloud.
The CloudFlare network can only proxy web traffic over port 80 and 443. The following subdomains should be marked with a gray cloud to prevent performance issues.
Common Records that should have a Gray Cloud (in alphabetical order):
calendar
cpanel
cvs
dev
direct
exchange
feed
feeds
ftp
ghs.google.com
git
host
imap
irc
jabber.tcp
local
localhost
mobilemail
mx
ns1
ns2
panel
pda
pop
repo
secure
sftp
sites
smtp
sql
ssh
ssl
svn
video
webmail
webstats