Final answer:
The most important factor in ensuring your business message is read is the subject line.
Step-by-step explanation:
The most important factor in ensuring your business message is read is the subject line. The subject line should be clear, meaningful, and represent the main point of your email. It is the first thing that the recipient sees and determines whether they will open your email or not. A good subject line makes it easier for the reader to prioritize and respond to your email.