Which envelope size is the minimum acceptable for correspondence?

The minimum acceptable envelope size for correspondence ensures that the content is presented professionally and can accommodate standard documents without folding. An envelope measuring 3.5" x 5" provides enough space for a standard letter or other correspondence while also being compact and easily manageable.

Envelopes that are smaller than this size, such as 3.5" x 4", would not adequately fit most standard documents and could result in them being folded or damaged. Additionally, the 4" x 5.5" size, while larger, goes beyond the minimum requirement, which is focused on the most compact yet functional size. Similarly, the 5" x 6" option is too large to be considered a minimum size. This choice of 3.5" x 5" strikes a balance between efficiency and usefulness for correspondence purposes.