Sending eamil from apex trigger

ContactEmailTrigger.apxt

// Send a Email to each new Contact
trigger ContactEmailTrigger on contact (before insert) {
 
    //get all email in the list
    List<Messaging.SingleEmailMessage> mails = 
      
  new List<Messaging.SingleEmailMessage>();
  
  for (Contact myContact : Trigger.new) {
    if (myContact.Email != null && myContact.FirstName != null) {
    
      // Step 1: Create a new Email
      Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
    
      
      // Step 2: Set list of people who should get the email
      List<String> sendTo = new List<String>();
      sendTo.add(myContact.Email);
      mail.setToAddresses(sendTo);

 
      // Step 3. Set email contents - you can use variables!
      mail.setSubject('Your contact detail are added'); //Subject of the mail and the body of the mail
      String body = 'Dear ' + myContact.FirstName + ', '; 
      body += 'According to the ContactEmailTrigger trigger';
      body += 'your contact details were added successful';
      body += 'For more details you can visit ';
      body += ' https://salesforceforfresher.wordpress.com/ ';
      mail.setHtmlBody(body);
    
      // Step 4. Add your email to the master list
      mails.add(mail);
    }
  }
  // Step 5: Send all emails in the master list
  Messaging.sendEmail(mails);
}