What feeling does writing in a form of a letter give instead of writing in a form of a poem?

Letters tend to be more formal.

Explanation:

In letters, most of the time your writing a formal letter. To inform somebody(communicate), or to persuade somebody. But in poem, you can be free with your thoughts and opinions. For example, in poem's people talk about love, freedom, politics and anything

the answer is mary made mudpies on monday.

remember alliteration is the occurrence of the same letter or sound at the beginning of adjacent or closely connected words.  

the answer is camped