Absolutely! A large block of unbroken writing makes the points you are making harder or impossible to pick out.
A business letter should be organized in a logical sequence.
- paragraph 1: why your are writing
- paragraph 2: the information you wish to convey (which can be two paragraphs or use bullets to highlight some points)
- paragraph 3: what you expect the recipient to do (if action is required); the information for the recipient to be able to contact you; and a thank you for the recipient's time and/or attention to the matter
