I'm doing a small newsletter software for my business, and I'm wondering what metrics should I collect. Obviously, bounces and clicks should be tracked, but I'm wondering should I track email opens (via an image or a bgsound element)?
Do popular webmail services and ISPs check for tracking images and possibly increase my spam score? I guess if it increases the chances of ending up in a spam filter, I'd rather not collect that metric.
Thanks.
As always it depends on the individual ISP and Webmail services. However, I can share some anecdotal evidence: I periodically use mailchimp to send out mass email notifications, and email opens are tracked in mailchimp using the same approach you mentioned (See following link for reference: http://kb.mailchimp.com/reports/about-open-tracking). I never experienced any issues with ending up in the spam folder, I have only had challenges with bounce backs and ending up in the Gmail promotions tab.
So based on the fact that some companies are already doing this, I have to say it probably won't increase your spam score.