In theory, I think your approach is fine, but in practice, there will always be opportunity to personalize. If you are really motivated, you can google the person and see if something interesting comes up, or you might already know the person tangentially from a conference, or there was an issue with the order that your team had to fix (a great opportunity to reconnect with a potentially unhappy customer). etc. Sure, a number of them might be exactly the same, but many of them won't be if you commit to the exercise and look for opportunities to form a relationship with these clients.