void On(AddedEmailToDomain e)
{
MailAddress mailAddress = new MailAddress(e.Email);
if (!state.Domains.ContainsKey(mailAddress.Host))
{
state.Domains.Add(mailAddress.Host, 0);
}
state.Domains[mailAddress.Host]++;
}
void On(AddedEmailToDomain e)
{
state.Emails.Add(e.Email);
}