Archiving Emails to Opportunities

Hello All, 

I am wondering if anyone is familiar with an easy way to archive emails directly to opportunities. 

To provide some context:

I am able to archive emails against leads, contacts, and accounts. However, when an opportunity is generated, the lead and contact show up in their respective sub sections in the opportunity, but the emails tab remains empty. 

Perhaps I am doing something wrong within my workflow, but it would be great to see all emails between myself and the contact for that opportunity to show up on the opportunity page, without having to click on the lead and leave the page. 

Any thoughts on this? Thanks in advance! :)