private static void SendEmailSequentially(string address)
{
var wasAddSuccessfull = _emailsQueue.TryAdd(
() => NotThreadSafetyEmailSender.SendEmail(address));
if (!wasAddSuccessfull)
{
throw new InvalidOperationException("Problem with sending an email.");
}
}
private static void SendEmailDirectly(string address)
{
NotThreadSafetyEmailSender.SendEmail(address);
}