Internet Service Providers do their best to protect your e-mail account from becoming inundated with spam messages. Therefore, they follow a protocol to determine if a message sent to you might be spam. If they think that it is based on the subject line and sender's address, they will automatically defer the message to the Junk Mail folder if you have your e-mail set up to segregate Junk Mail. Sometimes, this may include messages that you had intended to receive. This is why it is important to check your Junk Mail folder every day to make sure that messages you had intended to receive did not accidentally get placed there. If they did, you just need to move them to your inbox.