Minding the Details of Email
Minding the details of email — capitalization, punctuation, and so on — shows respect for the reader’s time. Most people find it easier and more pleasant to read a carefully edited email with appropriate capitalization and punctuation than they do an all-lower-case, punctuation-free message. If you disregard such details, you will distract from your content.
You also risk giving the impression that the recipient’s convenience is less important than your time — the small amount of time it would take to fix these minor problems.