I use tracking software on all my emails. I learned long ago to never say anything about it for fear of freaking them out. But I am thinking of making an exception. Getting a bit annoyed with people that tell me they just bought right before I called and yes, they did read my email but I didn't offer anything they couldn't get anywhere else. I am about to call BS on these folks and let them know they never opened the email nor did they bother to click through to the report. I figure they have already blown me off so why not expose them as the liar they are?