SMTP (simple mail transfer protocol) is an electronic standard for email transmission. When you receive an email in your inbox, most likely it is being sent from an SMTP server.
You can use it with personal emails, or even with your website if you are sending emails for things such as contact forms, newsletter blasts, or notifications. you can register and get a email package of 25000 free relays per month.

Check out our tutorial on how to send emails from SMTP Account.
Outgoing Mail (SMTP) Server: smtp.pigeonmails.com
Username: Pigeonmails account (delivery@pigeonmails.com)
Password: Pigeonmails password
Port: 25