IP Warm Up Thresholds - Segmentation Tool to Cap Audience?

[msahnd]

We are working on a segmentation plan for IP Warm Up. We are able to segment by domain and engagement fields but cannot find a tool within smart lists to put a cap on an audience besides 'random sample' which only supports percentages. Is there another tool/filter that would allow us to say 'select top 5,000 from List A', for example? Or any other solutions re: segmenting for daily sending thresholds?

Thanks!

[SanfordWhiteman · Accepted solution]

There's no internal way to do this. We use an external counter service to do exactly sized buckets. 

[msahnd]

Ok thanks - this is what we thought but wanted to confirm before creating an outside solution. Appreciate it.