Advanced Send Email Flow Action – Send email from Salesforce flow with CC, BCC, and email attachments

public without sharing class SendEmailInvocable {

    @InvocableMethod(
        label = 'Send Email by APEX'
        description = 'Sends a email to recipients without need of Email Alert. If set the Who ID or What ID then Activity is also created.'
    )
    public static void execute( List<Request> requests ) {
    
        for(Request request : requests){
            SendEmailViaApex(request.WhoId, request.WhatId, request.toAddresses, request.ccAddresses, request.bccAddresses, request.OWAddress, request.ReplyTo, request.Subject, request.TextBody, request.HtmlBody, request.ContentVersionIds);
        }
        
    }
    
    public static void SendEmailViaApex(String WhoId, string WhatId, String toAddress, String ccAddress, String bccAddress, String OWAddress, String ReplyTo, String Subject, String TextBody, String HtmlBody, list<String> ContentVersionIds){
        // Note, this is bound by Apex governor limits of no more than 10 emails can be sent per transaction.
        
        String CONTACT_KEY_PREFIX = Contact.sObjectType.getDescribe().getKeyPrefix();
        String LEAD_KEY_PREFIX = Lead.sObjectType.getDescribe().getKeyPrefix();
        
            list<OrgWideEmailAddress> OrgWideAddress = new list<OrgWideEmailAddress>([Select Id, Address FROM OrgWideEmailAddress WHERE Address = :OWAddress limit 1]);
            system.debug('OrgWideAddress::'+OrgWideAddress);
            
            if(OrgWideAddress.size() > 0){
                
                Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); 
                
                if(String.isNotBlank( WhoId ) ) {
                    String whoKeyPrefix = Id.ValueOf(WhoId).getSObjectType().getDescribe().getKeyPrefix();        
                    mail.setTargetObjectId( WhoId );
                    mail.setSaveAsActivity( ( whoKeyPrefix == CONTACT_KEY_PREFIX || whoKeyPrefix == LEAD_KEY_PREFIX ) );
                }
                
                //Record ID for which letter will be generated
                if ( String.isNotBlank( whatId ) ) {
                    mail.setWhatId( whatId );
                    if ( String.isBlank( mail.getTargetObjectId() ) ) {
                        mail.setSaveAsActivity( true );
                    }
                }
                
                mail.setOrgWideEmailAddressId(OrgWideAddress[0].Id);                
                mail.setSubject(Subject);
                if(String.isNotBlank(TextBody)){
                    mail.SetPlainTextBody(TextBody);
                }else{
                    mail.SetHtmlBody(HtmlBody);
                }
                
                mail.setInReplyTo(replyTo);
                
                List<String> toAddresses= toAddress.split(',');
                mail.setToAddresses(toAddresses);
                
                if(String.isNotBlank(ccAddress)){
                    List<String> ccAddresses= ccAddress.split(',');
                    mail.setCcAddresses(ccAddresses);
                }
                
                if(String.isNotBlank(bccAddress)){
                    List<String> bccAddresses= bccAddress.split(',');
                    mail.setCcAddresses(bccAddresses);
                }               
                
                if(ContentVersionIds?.size() > 0){
                    mail.setEntityAttachments(ContentVersionIds);
                }
                Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
            }
    }

    // -----------------------------------------------------------------

    public class Request {

        @InvocableVariable(
            label = 'Who ID'
            description = 'Email recipient and who the email Activity will be related to (User, Contact, or Lead). At least one of Who ID, To, Cc, Bcc Addresses must be set.'
        )
        public String whoId;

        @InvocableVariable(
            label = 'What ID'
            description = 'What the email Activity will be related to (Account, Case, Opportunity, etc.). Cannot be set if Who Id is a User record.'
        )
        public String whatId;
        

        @InvocableVariable(
            label = 'To Addresses'
            description = 'Comma-delimited list of email addresses. At least one of Who ID, To, Cc, Bcc Addresses must be set.'
        )
        public String toAddresses;

        @InvocableVariable(
            label = 'Cc Addresses'
            description = 'Comma-delimited list of email addresses. At least one of Who ID, To, Cc, Bcc Addresses must be set.'
        )
        public String ccAddresses;

        @InvocableVariable(
            label = 'Bcc Addresses'
            description = 'Comma-delimited list of email addresses. At least one of Who ID, To, Cc, Bcc Addresses must be set.'
        )
        public String bccAddresses;

        @InvocableVariable(
            label = 'Org Wide Address'
        )
        public String OWAddress;
        
        @InvocableVariable(
            label = 'Reply To'
            description = 'The email address that receives the message when a recipient replies.'
        )
        public String replyTo;
        
        @InvocableVariable(
            label = 'Subject'
            description = 'The email Subject.'
        )
        public String Subject;
        
        @InvocableVariable(
            label = 'Text Body'
            description = 'The text body of the email.'
        )
        public String TextBody;
        
        @InvocableVariable(
            label = 'HTML Body'
            description = 'The HTML body of the email.'
        )
        public String HtmlBody;
        
        @InvocableVariable(
            label = 'Content Version Ids'
        )
        public list<String> ContentVersionIds;

    }

}