Started at this shop mid 2020 and having grown my knowledge and industry specific skills the leadership wants me to move from only sourcing deals to closing our service package (pre-SaaS).
I inherited a ton of cold, stale, top of funnel pipeline. You know these deals, haven't spoken to us since the one time they did. Perhaps they open all our emails but never return the outreach. I have been here before and again I'm going back to ol' trusty. Try this one email that I have had great success with and let me know how it works for you!
Email Subject: It appears you have lost enthusiasm for this project
Email Body: write nothing, keep it blank (gmail may require you to enter a space in the body)
That's it, drop that dangle in their inbox and let it sit. Don't call, give 'em a few days and my guess is there will be a reply.
Hope this helps!