Most email marketers know they can track email opens, clicks and bounces. However, there’s a second common email marketing question: Can I see if my email lands in my recipient’s inbox or junk folder?
You can try what’s called “email seeding” or putting email addresses from various Email Service Providers onto your email lists so you can monitor where your email lands on each service.
A quick do it yourself way would be to have accounts on Gmail, Yahoo, Hotmail/Outlook, etc. and add those to your lists. I would also make sure to have seed accounts running Sendmail with a default SpamAssassin setup and a Microsoft Exchange with Outlook client setup, as these are the two most common private email server configurations. Many third party spam filtering solutions are based off of SpamAssassin filtering rules.
The disadvantage to the DIY approach is that you wouldn’t have direct access to private or corporate email systems. Professional email seeding services like Return Path, have a farther reach and claim to have access to a large number of ESP seed accounts.
Topic inspired by this Quora thread.