Can we save attachment in activity using apex

Question

I'm using an apex single email message to send an email with an attachment. Everything is working fine. But in the activity history, I can only see email body details but attachment not saved in activity.

I have checked "Always save email attachments" under "My Email to Salesforce".

List<Messaging.SingleEmailMessage> lstsendmails = new List<Messaging.SingleEmailMessage>();
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
Id template_id =  [SELECT id, name FROM EmailTemplate WHERE developername ='Send_Invoice_PDF'].Id;
List<String> toAddresses = new List<String>();
toAddresses.add('test@test.com');  // e.g email address                        
mail.setToAddresses(toAddresses);
mail.setWhatId(inv); // Custom object(Invoice) id
mail.setTargetObjectId(cont.Id); // Activity save in contact
mail.setSaveAsActivity(true);
mail.setTemplateId(template_id);
List<Messaging.Emailfileattachment> fileAttachments = new List<Messaging.Emailfileattachment>(); 
Messaging.Emailfileattachment efa = new Messaging.Emailfileattachment();
efa.setFileName(cv.Title);
efa.setBody(cv.VersionData); // File version data(blob)
fileAttachments.add(efa);
mail.setFileAttachments(fileAttachments);
lstsendmails.add(mail);

List<Messaging.SendEmailResult> sendEmailResults = Messaging.sendEmail(lstsendmails,false);

Please advise on this

Answer 1

Use:

mail.setEntityAttachments(new List<Id>(/*contentVersionIds*/))

instead of:

mail.setFileAttachments()