Most email clients block these by default, at least in a business setting. My advice is to check your audience first. Bounce-back report tracking could be use

Most email clients block these by default, at least in a business setting. My advice is to check your audience first. Bounce-back report tracking could be useful if you're checking emails are delivered. I've used this when emails that have to be delivered are delivered. This was mainly for compliance reasons - whether they're read or not, or end up in whatever user folder, was of little importance. That these emails are delivered successfully was paramount. The bounce-back reporting showed where customer contact failed and secondary measures were necessary to get back in contact. Your use-case may be different, but if anyone reading this is in a similar situation to ensure delivery but not readership, implement a simple server-side delivery/non-delivery report.