Remote MySQL connection fails (10060) - "Can't connect to MySQL server on domainname.com(10060)"
you need to make sure there is:

a user created that has remote access for example user@'x.x.x.x'

the two machines can establish a connection (they can ping each
other for example or access each another by another method) the port
is opened between the two machines

check your configuration file  my.ini/my.cnf for parameters like bind-address or skip-networking. Is there a blocking connection parameter
like:bind-address=a.a.a.a or skip-networking?

the service is up and running when you try to connect from the
other machine