You literally can't have an email service that doesn't process your emails somehow. Spam filtering and phishing protection has to work on the content of the email, the act of sending email needs to read parts of it to send it. At the absolute least they need to "read" your email to store it's contents and send/display them.
If that is something you want to prevent, then i think using any hosted email provider is completely out of the question. Email in general might be unusable if that is the level of privacy you are looking for.
I normally hate parroting back the "if you don't like it then don't use it" line of thinking, but in this case it's the only real option. Sure they could offer a special service with no scanning, spam protection, etc... But they'd still need to store and "read" your email to work, and they'd still need to be able to do some analytics to protect their system from you (you could be a bad actor that would act in bad faith, and they need to protect against that to keep the entire service running). For someone that doesn't trust that they aren't going to just "read" your email anyway even if they say they only use it for some very limited things like spam protection, an additional layer of "we promise we also won't do this" won't change anything.
If you want absolute control over exactly what bytes are sent and where they go, host your own email service. Just like how if you want to be completely 100% absolutely sure that nobody is going to spit in your food, and you don't trust anyone else to not spit in your food, you need to cook it yourself.
The OP mentioned Google reading their email and does not mention the context of advertising you assumed. Another poster pointed out that Google no longer scans Gmail for advertising purposes anyways: https://variety.com/2017/digital/news/google-gmail-ads-email....
I understand what you are saying about all email getting "processed" however, Google is doing way more to process email than spam protection or else they would not need a massive agreement and a separate page listing subprocessors and further breaking those subprocessors down by region and noting whether they are internal or external to Google.
I think my point is simply agreeing that I think it is too bad Google does all this "processing" of user data and that GSuite offers some protection, but not enough.
The subprocessesors page lists Google subsidiaries, datacenter subcontractors, and customer support contractors.
None of those things are "external people we automatically share your email with". They're "Google" and the people who you'd ask for help when you call a customer service line.
You literally can't have an email service that doesn't process your emails somehow. Spam filtering and phishing protection has to work on the content of the email, the act of sending email needs to read parts of it to send it. At the absolute least they need to "read" your email to store it's contents and send/display them.
If that is something you want to prevent, then i think using any hosted email provider is completely out of the question. Email in general might be unusable if that is the level of privacy you are looking for.
I normally hate parroting back the "if you don't like it then don't use it" line of thinking, but in this case it's the only real option. Sure they could offer a special service with no scanning, spam protection, etc... But they'd still need to store and "read" your email to work, and they'd still need to be able to do some analytics to protect their system from you (you could be a bad actor that would act in bad faith, and they need to protect against that to keep the entire service running). For someone that doesn't trust that they aren't going to just "read" your email anyway even if they say they only use it for some very limited things like spam protection, an additional layer of "we promise we also won't do this" won't change anything.
If you want absolute control over exactly what bytes are sent and where they go, host your own email service. Just like how if you want to be completely 100% absolutely sure that nobody is going to spit in your food, and you don't trust anyone else to not spit in your food, you need to cook it yourself.