Is it safe to auto-junk customers emails with a combination of letters and numbers by default?

Would you agree that it is safe to auto-filter and trash such email replies with a letter/number/freemail combination by default?

No, I wouldn't. As one little example, you would delete any feedback from me. I typically don't hand out my primary email address on such forms, I provide a secondary @gmail.com address, to avoid getting spammed.

Why do you get so many false answers, is it a sign of a problem somewhere else? In most markets, if so many feedback submissions are bogus, it's a sign of a deeper problem IMHO. Is there something about your site that sends the wrong kind of signals perhaps -- could your site look untrustworthy, like it's likely to send spam emails afterwards? Do people install your software just to play with it? Or is it just normal for the market you're in (fx kids entertainment, some social networks, etc)?

This finding might interest you -- in this A/B test, when all information was clearly marked as optional, the quality of the real submissions went up dramatically.

"In this case, 20% of the required email addresses entered on Version A’s form were bogus, whereas all of Version B’s email addresses were valid." Source: Which Test Won.

We ask for customer feedback about our software on uninstallation via a web form. In our experience, we only rarely get anything valuable out of this... [so should we] trash email replies with a letter/number/freemail combination?

So you've learned two things. The first is that you do occasionally get useful feedback - how's that working out? For instance, have you gained any actionable insights? Have you retrieved any lost customers?

The second learning is that, based on the web form you're using now, you're getting a lot of junk and an apparent correlation between trash-ready comments and letter/number/freemail. So you could be split testing to determine, for instance,

• What happens when you don't ask for an email address

• What you get (response rate, actionability) from fixed choice questions (instead of free text)

• What happens when you ask for just an email address, and only for people who want to give feedback

• etc

The short answer? Don't trash the responses, trash your response mechanism.

It sounds like you require people to provide feedback. Most people don't want to bother, so they just type junk.

Make your feedback truly optional, and you should get quality feedback. Of course, you'll suffer from selection bias, but it's better than no feedback and you won't have to sort through garbage all day.

What is the product/market space?

Do you require the user to enter feedback to complete the uninstall process or is it presented as an option (i.e., "Thanks for trying our software. If you have any suggestions on how to improve the product please leave feedback below?") with an easy way to bypass?