Why SingleEmailMessage.setFileAttachments() does not create visible attachments in the Activity Tab in Lightning Experience

Question

I'm sending emails like this:

Messaging.SingleEmailMessage m = new Messaging.SingleEmailMessage();
m.setToAddresses( new String[]{'[email protected]'} );
m.setSubject(       'test' ); 
m.setHtmlBody(      '...' );
m.setWhatId(        anyObjectId );
Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment();
efa.setFileName(cv.Title);
efa.setBody( pdfBlob );
efa.setContentType('application/pdf'); // does not work: (cv.FileType);
efa.setInline(false);
m.setFileAttachments( new Messaging.EmailFileAttachment[]{ efa });
Messaging.sendEmail(new Messaging.SingleEmailMessage[] { m });

Now this perfectly work and the sent email shows up at the record with anyObjectId in the activity tab.

It even shows the paper-clip icon for the attachment. Only that the attachment itself is not visible:

It should look like this (created by sending an email OUT using the LEX UI):

I'm pretty sure that there is a ContentDocument, ContentVersion and a ContentDocumentLink (aka "Share") missing. Looking at the ContentDocument records of emails sent via the LEX-UI it should look like:

Now I would gladly manually add the missing ContentDocument, ContentVersion and a ContentDocumentLink, but only I can't because I can't get the Id of the EmailMessage as described in this question: How to get the Id of an EmailMessage after sending a SingleEmailMessage with Messaging.SendEmail()?

Any ideas on how to solve this?

Answer 1

The trick is to insert a ContentVersion first and then use the Messaging.SingleEmailMessage.setEntityAttachments method with the ContentVersion Id. The attachment goes out with the email and is stored in Salesforce. Sample below attaches a PDF. It is not bulkified, but you get the idea:

ContentVersion cv = new ContentVersion();
cv.VersionData = <yourBlobHere>;
cv.Title = 'myTitle';
cv.PathOnClient = 'myTitle.pdf';
cv.Description = 'myDescription';
cv.isMajorVersion = true;
insert cv;

Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
// Set your mail parameters...
mail.setEntityAttachments(new list<Id> {cv.Id});

List<Messaging.SingleEmailMessage> listEmails = new List<Messaging.SingleEmailMessage>(mail);
List<Messaging.SendEmailResult> listMailResults = Messaging.sendEmail(listEmails, false);

Answer 2

The only solution I could figure at all is to sadly forget about the incomplete EmailMessage Salesforce has been created for us and start over from scratch by inserting a brand new EmailMessage having proper attachments.

This is very sad, because

• it's not even easy to delete the incomplete one with out a trigger and some kind of flagging it. So I just forget about it an let it rot.
• currently letting it rot doesn't much because I removed the line m.setWhatId( anyObjectId ); so that the crippled record is not showing up on the parent record.
• now my new EmailMessage has attachments, but lost the paper-clip indicating the attachments. Strangely the one without attachments Salesforce is creating has that paper-clip.

Im still looking for a better and cleaner solution on this.

@Salesforce is that overall behavior "as designed" and considered a feature - or a bug? I would love not to have to do all this on my end. It feels wrong.

Answer 3

You need to set m.setEntityAttachments(lstContentVersionIds); where lstContentVersionIds is the list of contentversionIds of the files attached.

Messaging.SingleEmailMessage m = new Messaging.SingleEmailMessage();
m.setEntityAttachments(lstContentVersionIds);

Now you will be able to see the attachments as well.

Answer 4

You can get the email message Id on a trigger on EmailMessage. Then you can add manually the missing relationships.