[KingOfCoders]

"Send reconfirmation emails to people that have not interacted with your email (no opens or clicks)"

How can I check opens? I'm not aware of any reliable way to check this. Mail clients not loading pixels means the software is unaware of opens?

[jeroenhd]

I personally tend to enable delivery/read receipts for new email domains. Big providers will often send you a notification for delivery at least, and prompt for the read receipt.

You can also track your DMARC statistics and figure out what mail domains tend to not deliver your email.

[matt_heimer]

Same way as always, image loading. If image URLs are unique and external then you can track their opening. Not all users will allow it so you also track clicking on in email links.

[TylerE]

Doesn't just about every mail service proxy, and often preemptively fetch those?

[jeroenhd]

Not every service, buy many of them do.

[TylerE]

I'm quite sure GMail does... which is basically the entire internet as far as mail delivery.

[toomim]

Maybe because they click a link in the confirmation email?