how can I block incoming emails in Apple Mail OSX Mountain Lion?, how can I block incoming emails in Apple Mail OSX Mountain Lion?

You can't. You can mark them as spam within Mail and maybe the filter will catch them.

Who is your ISP? You need to contact them.

Create a rule to delete or sequester the messages. Select Mail > Preferences > Rules. Click the question-mark icon and read the built-in help.

This will depend on the nature of the emails, and if there is a common aspect to them such as the subject or the sender's e-mail, then you can create a rule in Mail's preferences by selecting one of the spam emails in your inbox, and then go to the Rules section of the Mail preferences and create a new rule. The sender's email will be listed in the rule, and you can set an action to automatically trash any incoming messages from that sender.

You can also change the rule to apply to a specific subject line, or some text in the body, etc.

Mail (Mountain Lion): Manage messages using rules

Depending on your email service/ISP, you may be

able to simply log into your mail account online and

set up filtering there. Then the offending mail would be

put in trash (or deleted) at that point and never reach

Mail on your Mac (or iDevice).

If you don't have that capability, then follow previous advice.

Never used rules before. Was getting messages from Asia. Do not know what language. Applied the rules to delete the emails and they disappeared after applying the rule. Interesting too, how as you highlight the next email with a different email address, then click the + sign to add another email address, the system adds the email automatically. Thank you for the suggestion. It worked perfectly.