Hi,

Thanks for posting your question on Pega Support Community.

I think you can refer the binary rule to your correspondence rule. 

Also, please check the below code and below article which might help you:

Try this out:-
1)Create a new page called Attachment Page of class Data-EmailAttachments
2)Use the java method to write the following piece of code.Pls note that the variable below datatoattach should contain a Base 64 Encoding of the entire attchment.Use Base64Encode expression to do that in some prev step.

------------Start of code-----------------------------
ClipboardPage page_EmbedAttachment = null,
page_AttachmentPage = tools.findPage("AttachmentPage");

ClipboardProperty prop_pyAttachment = null;

try {

prop_pyAttachment = page_AttachmentPage.getProperty(".pyAttachments(<append>)");
page_EmbedAttachment = prop_pyAttachment.getPageValue();

page_EmbedAttachment.putString(".pyData",datatoattach);
page_EmbedAttachment.putString(".pyName","XYZ.xls");
page_EmbedAttachment.putString(".pyDecode","true");
page_EmbedAttachment.putString(".pyRemoveXML","false");

} catch (Exception e) {

tools.getPrimaryPage().addMessage( e.getMessage() );

}

--------------End of code ----------------------------------

3)Call SendEmailNotification and send "AttachmentPage" in the parameter AttachmentPage.

It should send out the email with the attachment XTZ.xls.

You can look into SetEmailAttachments that contains a similiar code.

https://community1.pega.com/community/pega-support/question/send-email-attachment-without-work-object