return of post in a sentence

Examples

1. Are there to be fine distinctions, such as, if the words are  unless I hear from you by return of post, & c .,  it is necessary the letter should reach him, but  let me know by return of post,  it is not; or if in that case it is, yet it is not where there is an offer without those words.
2. Are there to be fine distinctions, such as, if the words are  unless I hear from you by return of post, & c .,  it is necessary the letter should reach him, but  let me know by return of post,  it is not; or if in that case it is, yet it is not where there is an offer without those words.