You can start a newsletter using just Gmail. You can create an email list by adding subscribers to your contacts. You must compose your message and send it to your list. You should be cautious with Gmail's sending limits. You can only send emails to a certain number of recipients per day. You might need to split your list into smaller groups to avoid hitting these limits. You should also ensure that your emails comply with spam regulations. You can add a personal touch to your emails but you might find dedicated email marketing platforms more efficient for larger lists.