E-mail Follow-Up is an add-in for Microsoft® Outlook® that allows (and reminds you!) to send follow-up e-mail messages if a reply has not been received within a specified time-frame. E-mail Follow-Up will watch for messages and show an alert when a reply has not been sent.
This add-in for Outlook also allows you to send a follow up message using a predefined template to remind the recipient that the reply hasn't been sent.
"I wrote to them and they didn't answer!" - this is a typical ending for many negotiations though the result could have been different if the message had been noted in time and resent or maybe even followed up with a telephone call.