CLASS :-


 public class UserDML
    {
         public static void sendEmailtoUser(List <User> newUsersTrigList) {
              
                list<EmailTemplate> Temp = new  list<EmailTemplate >([SELECT id FROM EmailTemplate WHERE DeveloperName = 'User_Welcome_Email_Template_1' LIMIT 1]);
                //Collects all Users Ids to be used on query
                Set <Id> newUserIds = new Set <Id>();
                for (User u : newUsersTrigList){
                    if ( u.Send_Welcome_Email_to_User__c ) {
                        newUserIds.add(u.Id);
                    }
                }
                
                //Retrieve list of users created/updated from Trigger
                list <User> newUsersList = [Select Id, ProfileID, Send_Welcome_Email_to_User__c From User Where Id in : newUserIds];
                SystemEventLogDML sLogDML = new SystemEventLogDML();
                list<System_Event_Log__c> SysEventLogsList = new list<System_Event_Log__c>();
                
                try {
                    if (newUsersList.size() > 0){
                        Send_Email_to_Users_Settings__c EmailUserSettings = new Send_Email_to_Users_Settings__c();
                        list <Messaging.Singleemailmessage> msglist = new list <Messaging.Singleemailmessage>();
                        list <User> upUsersList = new list <User>();
                        
                        for(User u :newUsersList){
                            //Send Email to Users based on its Profile
                            EmailUserSettings = Send_Email_to_Users_Settings__c.getValues(u.ProfileId);
                            Messaging.Singleemailmessage msg = new Messaging.Singleemailmessage();
                          If(EmailUserSettings != null){
                            msg.setTemplateId(EmailUserSettings.Email_Template_ID__c);
                            }
                            else
                            {
                              msg.setTemplateId(Temp[0].id);
                            }
                            msg.setTargetObjectId(u.Id);
                            msg.setSaveAsActivity(false);
                            msglist.add(msg);
                            
                            //Sets flag back to unchecked after sending the message to the user's email
                            u.Send_Welcome_Email_to_User__c = false;
                            upUserslist.add(u);
                        }
                        
                        //Sends email to Users
                        if (EmailUserSettings.Email_Template_ID__c != null){
                            Messaging.sendEmail(msglist);
                        }
                        //Updates all users' Send Email checkbox
                        update upUserslist;
                    }
                    
                }
                catch (Exception e ){
                    SysEventLogsList.add(sLogDML.generateSysLog('UserDML.sendEmailtoUser', e.getMessage(), '', slogdml.EvtType[0], UserInfo.getUserId()));
                }
            }

 Hi,

Getting this error while creating user. i have a checkbox field on user object send_mail_c . if its true then it sends a welcome mail template to user. i have created a profiles market and sales in custom settings and attached a template ID to it. but my requirement is to send a default mail when the profile doesnt exists in custom setting.

Trigger below :-

trigger UserMasterTrigger on User(Before insert, Before update, After Update, After insert)
{
    if(trigger.isBefore)
    {
        if(trigger.isInsert)
        {
            //call the handler for the before insert trigger event
            //population of Federation Id with SSO value
            //population of Manager lookup based on Manager SSO value
            UserTriggerHandler handler = New UserTriggerHandler();
            handler.onBeforeInsert(trigger.New);
        }
        
        if(trigger.isUpdate)
        {
            //call the handler for the before update trigger event
            //population of Federation Id with SSO value
            UserTriggerHandler handler = New UserTriggerHandler();
            handler.onBeforeUpdate(trigger.newMap, trigger.oldMap);
        }
    }
    if(trigger.isAfter){
        if(trigger.isInsert)
        {
            //call the handler for the after update trigger event
            //sending of Email to newly created Users
            UserTriggerHandler handler = New UserTriggerHandler();
            handler.onAfterInsert(trigger.newMap, trigger.oldMap);
        }
        if(trigger.isUpdate)
        {
            //call the handler for the after update trigger event
            //population of Manager lookup based on Manager SSO value of records outside of the trigger batch
            //sending of Email to updated users
            UserTriggerHandler handler = New UserTriggerHandler();
            handler.onAfterUpdate(trigger.newMap, trigger.oldMap);
        }
    }
}