Yes, email service providers such as Constant Contact, OmniSend and MailChimp help you stay compliant with laws and regulations related to email marketing, such as the CAN-SPAM Act in the United States. They often include features such as unsubscribe links and opt-in forms to help you stay on the right side of the law.
They make it easier to set your sender name, add a subject line and preheader text, use email message templates, and manage your lists of email recipients with ease.
Added to that, these services also optimize deliverability by adhering to best practices, such as managing bounces and spam complaints. If you send emails from your own email client, personal Gmail account, or server, your emails may be more likely to end up in spam folders or not be delivered at all.