delete from sales failed with exception SSL read: errno -5961

Hi,

I'm running a smart campaign to delete people from Marketo and also from #Salesforce. Our Marketo and SFDC instances have a one-to-one relationship, so that every person who exists in one system, exists in the other.

When I run the campaign to delete people and "Remove from SFDC = TRUE", some people are not being deleted, with the #error message of "Failed: delete from sales failed with exception SSL read: errno -5961"

Does anyone know what this error means and how I can fix it and delete these people from both systems?

Thank you so much!!

-Leticia