refs 551532f874
refs https://github.com/TryGhost/Team/issues/3324
- After analyzing data dumps, the data revealed that we have extra data from a stray batch. The filtering logic manually filters out the data to the recipients that belong to a "current batch".
- Hunting down the root cause of the data mixup proved to be too expensive of an investigation, so this is a "good enough patch" to deal with the problem.
- Most likely cause is the concurrent batch sending, but reducing the concurrency would be too expensive of a performance price to pay instead of filtering the data rarely.