Don't worry, I am not a hacker and I don't break into e-mail addresses. What I had in mind was a simple e-mail checker service that checks whether an e-mail address exists or not. Something like this:
You can go there and do the tests yourself. If the result is positive, and the e-mail address (mailbox) exists, it means the owner can receive e-mails there; however, there are cases when an e-mail address is active, but new e-mails don't come in. For example, if the mailbox quota has exceeded (no more space). A sender will immediately be notified via automatic reply that the delivery failed, and such message usually contains short reason and the error code, such as "Error: 550 Mailbox Quota Exceeded". The owner will need to delete some of the e-mails (usually those containing big attachments) to free up the space for new e-mails, and the sender will need to re-send the same e-mail since the previous one won't be automatically delivered.
As far as blocking specific senders go, most e-mail services, including Hotmail, don't inform the sender that they have been blocked nor that their e-mail wasn't delivered. It works in a way where the owner either doesn't receive an e-mail from a blocked sender, or does receive it, but the e-mail goes directly to "Spam" or "Trash", without a notification of a new e-mail, and such e-mails are usually automatically deleted within 30 days.
So, if you have been blocked, you wouldn't have received any automatic reply. To test if your account can both receive and send e-mails, you can send a test e-mail to yourself. The same e-mail should then be visible in both "Inbox" and "Sent Items".
If you received an automatic reply, check the sender of the automatic reply. If it was from "Postmaster", it means there was a problem with the delivery, so check for reason or error code; however, if it was from the same e-mail address to which you sent an e-mail, it could mean that the owner simply enabled the Automatic reply option that would automatically reply to all e-mails containing the predefined message. Such feature is usually used when you are out of office for a few days, and want to inform the senders that you are away, and will reply later.
I hope this information helps! If you require further assistance, let me know.