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Having worked in IT for decades sending millions of emails into an the major inbox providers I can say that unless your brand is being targeted by a coordinated campaign, spending the time to set up processing of both the transaction and forensic emails isn't worth the effort. If you are a smaller shop, consider not spending a great deal of time on it until you actually need it.

Edit to say if sending to Gmail recipients take the time to set up the free Postmaster tools provided by Google to give you the ability to keep an eye on both IP and domain reputation and use "good" content email streams on your lower reputation IPs to bring them back into acceptable ranges while moving transactional emails around to avoid watering down remarks email streams with high-engagement content.