Thanks for your commit!
I believe that using glob for the implementation of wildcards is more suitable, as glob is designed for this purpose. The current implementation for ExcludeDomain is little redundant and complex. I prefer just define as ExcludeDomainGlob []glob.Glob , and check it like

for _, g := range m.config.ExcludeDomainGlob {
	if g.Match("xxxx", g) {
		// should exclude this domain
		return true
	}
}
return false

Also, ExcludeDomainGlob should be compiled first according to the user config.

You can simply use wildcard for exclude domain now, for example

*.mozilla.net
*.mozilla.com
*.mozilla.org
*.firefox.com
*.google*.com