Flow Variable of Email addresses to Invocable Apex action

Question

I'm trying to pass in the flow variable collection of Email addresses to Apex action to send out one email to each email address. I got some idea from Question, the code works fine when i ran it from anonymous window (by passing list of Email addresses) but it doesn't work with the flow. Can someone point me what I'm doing wrong?

Here is the code

public class SendEmailAction {
    @InvocableMethod(label='Send SE Email Notification') 
public static void SendSENotification(List<List<String>> Emailaddresses){
    List<String> getEmails = new List<String>();
    
    //List<string> getEmail = Emailaddresses[0];
    List<OrgWideEmailAddress> lstEmailAddress=[select Id from OrgWideEmailAddress WHERE Address='[email protected]'];
    List<EmailTemplate> SEEmailTemplate= [Select Id, Name, DeveloperName 
                           from EmailTemplate 
                           where DeveloperName= 'Safety_Event_New_Event_Reported'];
         
     Messaging.SingleEmailMessage[] mails = new Messaging.SingleEmailMessage[0];
            
    for(List<String> Ids : Emailaddresses) {
        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
        mail.setTemplateId(SEEmailTemplate[0].Id);
        mail.setTargetObjectId(UserInfo.getUserId());
        mail.setToAddresses(getemails);
        mail.setSaveAsActivity(false);
        mails.add(mail);
        mail.setOrgWideEmailAddressId(lstEmailAddress[0].Id);
    }
   Messaging.sendEmail(mails);
}
}

Flow

Answer 1

this should work:

public class SendEmailAction {
  @InvocableMethod(label='Send SE Email Notification') 
  public static void SendSENotification(List<List<String>> emailAddressCollections){
    
    List<OrgWideEmailAddress> lstEmailAddress=[SELECT Id 
                          FROM OrgWideEmailAddress 
                          WHERE Address='[email protected]'];
    List<EmailTemplate> SEEmailTemplate= [SELECT Id, Name, DeveloperName 
                           FROM EmailTemplate 
                           WHERE DeveloperName= 'Safety_Event_New_Event_Reported'];
         
    Messaging.SingleEmailMessage[] mails = new Messaging.SingleEmailMessage[0];
            
    for(List<String> emailAddresses : emailAddressCollections) {
        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
        mail.setTemplateId(SEEmailTemplate[0].Id);
        mail.setTargetObjectId(UserInfo.getUserId());
        mail.setToAddresses(emailAddresses);
        mail.setSaveAsActivity(false);
        mails.add(mail);
        mail.setOrgWideEmailAddressId(lstEmailAddress[0].Id);
    }
    Messaging.sendEmail(mails);
  }
}

I renamed your variables to be a bit clearer (as you are dealing with lists of lists)

Your flow looks OK as far as I can see. use the Summer 21 Record-Triggered Flow debugging to make sure that a collection of strings are passed in the flow interview to the invocable apex. If not, dig deeper into the Flow