We're currently working on the customer sign-up/"onboarding" for Feature Upvote. We've been debating why and how we should do email verification for new customers.
So far the main reason I can think of is to ensure that customers entered their correct email so that if they forget their password in three months time they can use the "reset password" option.
When new signups need to switch to their email, there is a good chance they'll be distracted by their inbox, and we'll lose their attention, and they may never continue our onboarding.
Are there other important reasons for doing email verification? Do you do this in your SaaS?