What is the maximum weight limit for flat-rate envelopes and small flat-rate boxes for Priority Mail International?

The maximum weight limit for flat-rate envelopes and small flat-rate boxes for Priority Mail International is indeed 4 pounds. This weight limit allows for a wide range of items to be sent internationally without the need for weighing individual parcels, which simplifies the shipping process. The flat-rate nature of these services means that regardless of the weight, as long as it is within this limit, the sender pays a standardized rate. This makes it more convenient for customers sending items internationally, as they can plan their shipping costs upfront without concerns about fluctuating prices based on weight within the specified limits.

When considering the other options, they do not align with the established limits for flat-rate envelopes and boxes, which is why they are not applicable in this context.