Attached below is the trigger...its an old trigger that I am digging up now. The goal of the project is to assign an owner to a lead based on postal code. So there are two objects in play: Lead and a custom object called ZIP_Code__c. We have manually assigned a field called Dealer_Lead_Contact__c with an email address to every record in the Zip Code object.

Every time this trigger is ran, on new or updated lead, I want to send an email to the Dealer_Lead_Contact__c. I plan to do this with the process builder but need to first populate an equivalent field in the Lead object.

So, in the trigger, I want to add a functionality that will use the zip code field in the lead object (Zip_Code__c) and search the zip code object (ZIP_Code__c) for a match. If it finds a match, assign the dealer lead contact field in the lead object (Dealer_Lead_Contact__c) with the dealer lead contact in the zip code object (Dealer_Lead_Contact__c)?

Currently the Dealer_Lead_Contact__c is a text field, the email address will be coming in the form of ***@***.com as a column in an excel sheet and uploaded to the Zip code object with the data loader. Not sure if there is a better way to fire an automatic email than using the text as text.  Any help is appreciated!



trigger LeadAssignOwnerByPostalCode on Lead (before insert, before update) {

    List<Lead> lList = new List<Lead>();
    
    Map<String,ID> zipCodeMap = new Map<String,ID>();
    
    Map<id, User> userMap = new Map<id, User>();
    
    Set<String> userIds = new Set<String>();
    
    Set<String> zipCodeString = new Set<String>();
    
    List<Zip_Code__c> zipCodeList = new List<Zip_Code__c>();
    
    List<Messaging.SingleEmailMessage> listmail = new List<Messaging.SingleEmailMessage>(); 

    for(Lead l: Trigger.new)
    {       
        
        System.debug('LeadAssignmentByZipCode -- Do_Not_Use_ZipAssignment_del__c ' + l.Do_Not_Apply_Zip_Assignment_Rules__c);
        
        //Do_Not_Use_ZipAssignment_del__c
        if(l.Do_Not_Apply_Zip_Assignment_Rules__c == true) continue;
        
        if(Trigger.isUpdate){
            System.debug('LeadAssignmentByZipCode -- Update Trigger -- ');
            Lead oldLead = Trigger.oldMap.get(l.id);
            if(l.PostalCode.equals(oldLead.PostalCode)) continue;
        } else
            System.debug('LeadAssignmentByZipCode -- Insert Trigger -- ');
        
        
        if(l.PostalCode <> null){
            zipCodeString.add(l.PostalCode);
            System.debug('LeadAssignmentByZipCode -- Lead -- ' + l.Name + ' Zip -- ' + l.PostalCode);
                
        }
    }
    
    if(!zipCodeString.IsEmpty())
    {
        System.debug('LeadAssignmentByZipCode -- Leads To Process ' + zipCodeString.size());
        
        zipCodeList = [SELECT  id, Name, UserAssigned__c  FROM Zip_Code__c WHERE Name IN: zipCodeString ];
        
    } else{
        System.debug('LeadAssignmentByZipCode -- No Leads To Process');
    }
    
    
    if(!zipCodeString.IsEmpty()){
        
        System.debug('LeadAssignByZip --- zipCodeString Count --> ' + zipCodeString.size());
        
        
        for(Zip_Code__c z: zipCodeList){
            
            if(!zipCodeMap.containsKey(z.Name)){
                zipCodeMap.put(z.name, z.UserAssigned__c);
                userIds.add(z.UserAssigned__c);
            }
            
        }
    }else
        System.debug('LeadAssignByZip --- zipCodeString Count --> zero');
         
        
    if(!userIds.IsEmpty()){
        
        System.debug('LeadAssignByZip --- userIds Count --> ' + userIds.size());
        userMap = new Map<id,User>([SELECT id, email FROM User WHERE id IN: userIDs]);
        
    }else
        System.debug('LeadAssignByZip --- userIds Count --> zero');
            

    for(Lead lead: Trigger.New) {
        
        if(lead.Do_Not_Apply_Zip_Assignment_Rules__c == true) continue;
        
        if(Trigger.isUpdate){
            System.debug('LeadAssignmentByZipCode -- Update Trigger -- ');
            Lead oldLead = Trigger.oldMap.get(lead.id);
            if(lead.PostalCode.equals(oldLead.PostalCode)) continue;
        } else
            System.debug('LeadAssignmentByZipCode -- Insert Trigger -- ');
        
        
        if(zipCodeMap.containsKey(lead.PostalCode)){
            
            Id owner = zipCodeMap.get(lead.PostalCode);
            lead.OwnerId = owner;
            
            String inSubject = 'Lead Assignment Change' ;
            String inPlainTextBody = '';
            
            //if(CheckOrganizationID.IsProduction())
            //  inPlainTextBody = 'A lead has been assigned to you:  https://na.salesforce.com/' + lead.id + '  Please click for details.\n\n';
            //else
            //inPlainTextBody = 'A lead has been assigned to you: ' +  CheckOrganizationID.getServer() + '.salesforce.com/' + lead.id + '\n\nPlease click for details.\n\n';
            inPlainTextBody = 'A lead has been assigned to you: \n\n' + URL.getSalesforceBaseUrl().toExternalForm() + '/' + lead.Id + '\n\nPlease click for details.\n\n';
            
            inPlainTextBody += 'Name: ' + lead.FirstName + ' '  + lead.LastName + '\n';
            inPlainTextBody += 'Company: ' + lead.Company + '\n';
            inPlainTextBody += 'Street: ' + lead.Street + '\n';          
                
            inPlainTextBody += 'City, State, Zip Code: ' + lead.City + ', ' + lead.State + ' ' + lead.PostalCode + '\n';
            

            if(lead.Email <> null)
                inPlainTextBody += lead.Email + '\n';   
            if(lead.Phone <> null)
                inPlainTextBody += lead.Phone + '\n';                       
            
            String toAddress = '';           
            
            Messaging.Singleemailmessage mail = new Messaging.Singleemailmessage();
            
            mail.setSubject(inSubject);
            list<String> ToAddr = ToAddress.split(',');
            
            if(userMap.containsKey(owner)){
                User u = userMap.get(owner);
                //toAddress = u.Email;
            }
            
            //mail.setToAddresses(toAddr);
            mail.setPlainTextBody(inPlainTextBody);
            mail.setSenderDisplayName('Salesforce Administrator');
            mail.setSaveAsActivity(false);
            mail.setTargetObjectId(owner);
            
            listMail.add(mail);

        }   
        
    }   
        
    if(!listMail.IsEmpty()){
        
        try{            
            System.debug('LeadAssignByZip Sending Mail listMail Size ---> ' + listMail.size());
            Messaging.SendEmailResult [] results = Messaging.sendEmail(listmail);  
        
        }catch (Exception Ex)
        {
            system.debug('ERROR occured while sending email==>'+ String.ValueOf(Ex));
        }        
            
    } else{
            
        System.debug('LeadAssignByZip listMail Empty No Mail to send..... ');
    }               
    
}