You’ve just implemented a new instance, process, catalog item, or workflow.
You put all that time and thought, and effort into making sure that everything that anyone could possibly want to know about, results in an email notification to all potentially-interested parties, so that nothing can possibly slip through the cracks!
And yet… somehow… you notice that users are still, often, not taking action where appropriate. Didn’t they get the email!?
You look through the email logs, and find that - indeed - among the sea of notifications that had been sent to them, there it is: the email telling them that they need to do something.

You: "Hey [approver], it looks like we've been waiting for you to approve this request for a couple of weeks now. Haven't you got any of the notification or reminder emails?"
Approver: "Uh... I have notifications from ServiceNow filtered to junk..."

Most of us have had some variation of this conversation.
Maybe they’ve filtered emails from ServiceNow to their junk folder. Maybe they’ve got a separate “special” folder just for SN emails, where they can be auto-routed and never looked at. Maybe they’ve just got so accustomed to 90% of the emails they get from ServiceNow being irrelevant or non-actionable for them, that they’ve got into the habit of just deleting them as soon as they show up.
The result is the same: your users aren’t getting your emails!

A notification that’s never read, is worse than no notification at all.

So, how do we stop this vicious cycle? -- Let’s talk about notifications in ServiceNow.