If your organization needs to update the email addresses of a number of Sales Navigator users in Account Center, you can do so via CSV upload.
When you update the email addresses of users in bulk, the welcome email is not sent to users. This welcome email is normally sent only to new users. Also, if a user hasn't previously accepted their invitation, they'll need to accept the invite and go through the onboarding process. But if a user has previously accepted the invitation, they won't have to go through the onboarding process again.