11 options to send emails from Salesforce
Options + things to know before you start sending emails.
Salesforce Email Options:
Tips to start mailing your customers/partners from Salesforce:
Know your daily email limits while sending emails.
Regularly monitor emails logs.
Make use of Email Composer + Templates + Macros efficiently for sending out emails along with attachments.
Check available options of email deliveries: Gmail/Office365, best if you can enable email relays if you have your own business email domain.
Decide carefully which emails have to automated and which to be sent manually respecting the daily email limits.
Bonus point: List emails can be used for marketing your customers however I recommend if you have very big list of customers/businesses who you want to market instead of Transactional emails consider opting for any of Pardot/Marketing Cloud/MailChimp/SendGrid as per feasibility.