Apex Trigger To Insert/Delete/Update a record

trigger EventTeamMemberTrigger on Event_Team_Member__c (after insert,after update,before delete) {
if(trigger.isAfter && (trigger.isInsert || trigger.isUpdate) ){
//Start of new code
set<id> pids = new set<id>()
for(Event_Team_Member__c eTM : Trigger.new){
    pids.add(eTM.Team_Member__c);  
}
map<id,User> pmap = new map<id,User>([select id,email from User Where id in: pids ]);
//End of new code
for (Event_Team_Member__c eTM : Trigger.new) 
{ 
  if(eTM.Team_Member__c != null){ 
    User tmm = pmap.get(eTM.Team_Member__c);
    String userEmail = tmm.email; // This is the Path Where I can get the Email Id of the Team_Member__c(user)
    Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
    String[] toAddresses = new String[] {userEmail}; 
    mail.setToAddresses(toAddresses); 
    mail.setSubject('Automated email: Contact created/updated'); 
    String body = 'Contact created/updated' ; 
    mail.setPlainTextBody(body); 
    Messaging.sendEmail(new Messaging.SingleEmailMessage[]{mail});
    }
} 
}
if(trigger.isBefore && trigger.isDelete ){
//Start of new code
set<id> pids = new set<id>()
for(Event_Team_Member__c eTM : Trigger.old){
    pids.add(eTM.Team_Member__c);  
}
map<id,User> pmap = new map<id,User>([select id,email from User Where id in: pids ]);
//End of new code
for (Event_Team_Member__c eTM : Trigger.old) 
{ 
  if(eTM.Team_Member__c != null){
    User tmm = pmap.get(eTM.Team_Member__c);
    String userEmail = tmm.Email;
    Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); 
    String[] toAddresses = new String[] {userEmail}; 
    mail.setToAddresses(toAddresses); 
    mail.setSubject('Automated email: Contact deleted'); 
    String body = 'Contact deleted'; 
    mail.setPlainTextBody(body); 
    Messaging.sendEmail(new Messaging.SingleEmailMessage[]{mail});
  }
}