Workflow on Email Sent

[Nikhil Bhagat]

I am using SugarCRM 5.5 professional
NCS Computech is dealing in AV.
We get renewal data every month from our principal company.

Based on the data, I fire email to the customers telliing them of the renewal due.

What i want is a workflow firing to the customers email id of a reminder to the renewal email I had sent.
How do i do it? How do i set it?

[stasila]

I am also interesting how to achieve that..