@the permalinks 

Before answering your question just one note.. You named the segment “Customers who haven’t purchased for the last 120 days” so I assume you want people who placed at least one order before (because you call these people Customers). So probably you need another definition for your segment and that is placed order at least once overall.. so the segment would look something like this:

• placed order at least once overall (these are customers)
• placed order zero times in the last 120 days
• person is not suppressed for email

Then about people who are already in the segment there are few things you can do:

1. You can back populate the flow or now that is called Add past profiles (in Manage Flow). Issue you may face here is if you have a dynamic code in the flow this would be more complicated. But if not you can just add the profiles that are already in the segment to go through the flow.
2. Clone this flow triggered by an empty list. Prepare that flow and make it live, and then download the people from the segment above and upload them to the list and with that they will trigger the flow.
3. Or what I would suggest is this third option because this sounds like Win Back flow is to create it like usual Win Back flow. Trigger Placed order flow filter Placed order zero times since starting this flow, add the time delay for the first email in this flow to 120 days and then simply back populate / add past profiles to the flow. This would be probably the most appropriate (just it wont email all the people from your segment but only those who didn’t placed orders in last 120+/- days depending on when they placed their order and how long is your flow) For the people who wont get in this flow with adding past profiles you can do the 2nd option i guess..

Not sure if the above Win Back solution modified would best solve my question. I want to send a reminder to customers that ordered custom printed products a year ago to see if they want more. I have set up a Standard WinBack flow with 3 emails, I was planning to upload the list of customers who purchased printing garments > 12 months ago to send the flow to.

• placed order at least once overall (these are customers) - They have placed the order offline as customised goods aren’t automated through Shopify. Hence manually uploading the list
• placed order zero times in the last 365 days
• person is not suppressed for email

The challenges I am having are:-

1. In the flow I have setup, the trigger seems fixed on MUST having received an online order from Shopify.
2. I only want the flow to go out to customers who purchased customised goods offline, I don’t want it to go to all customers that have placed an order more than a year ago.
3. I don’t want new online orders to be added into this flow.
4. I would like to initiate the flow occuring to the segment/list of my choosing
5. Does Klaviyo offer a list cleaning service (Hard bounce removal) similar to Omnisend, as these customers are over a year old and were offline, I would like to double check there addresses are still correct, before I try and email out to them?