We have recently experienced a very high bounce rate all of a sudden with Verizon users. This appears to have been an issue in the past, but I wanted to double-check the best practice for resolving this. Currently we have stopped sending to anyone with a Verizon email. Which of the following would be best to get this resolved ASAP?

1. Create a segment of engaged Verizon addresses (who have opened an email in the past month) and send to this segment separately alongside our regular lists. 
2. Create a Very highly engaged, highly engaged and engaged Verizon segment and start sending to each after a week (eg. week 1 only the very highly engaged, week 2 add in the highly engaged etc)? 
3. Wait and see if it is a Verizon issue and try sending to Verizon customers in a day or two? 

My other question was, if we separate the engaged Verizon users, do we just stop sending to the unengaged ones indefinitely or is there a way to bring them back in eventually? 

Thank you! 

(Aware there is a Klaviyo help document about this but it isn’t too clear.)