One new feature sure to be popular with those who constantly receive iMessage spam is the ability to filter, and then mark messages as "Junk."
If you've ever received a message claiming you've won a cruise or a Best Buy gift card, and the bubble was blue. you've been subjected to iMessage spam.
The process enable filtering of iMessage spam. Screenshot by Jason Cipriani/CNET
You can enable the new iMessage filter by launching the Settings app, selecting Messages and then moving the switch next to Filter Unknown Senders to the on position.
Return to the home screen and launch the Messages app. You should know see two different
columns in your conversation view. One column is titled Contacts & SMS. the other is called Unknown Senders.
Screenshot by Jason Cipriani/CNET
Unknown senders is where iMessages you receive from phone numbers or email addresses not in your address book will be found. When you view a conversation filed in the unknown column, you'll have the option to mark it as Junk and delete the conversation from your phone. Additionally, the sender's information will be sent to Apple for the company to use in an effort to reduce spam.
If you don't see the option to filter your messages, update to iOS 8.3 by going into Settings > General > Software Update .