Response-Msg-03:
... pls see my earlier message ...
in above mentioned all email-server services / solutions , user's email content can be seen by email-service provider's admin, etc, etc.
So email's content itself need to be encrypted, by the sender, for the receiver.
Sender & receiver need to have+use their own digital key (aka: certificate) to encrypt & to decrypt.
OpenPGP based solutions, OpenPGP based GnuPG / GPG based solutions, & the original PGP based solutions (from which OpenPGP was created) , can encrypt email's content, and can decrypt email's content.
SMIME certificate based solution can also encrypt email's content.
https://en.wikipedia.org/wiki/OpenPGP
OpenPGP allows end-to-end encryption in between a pair of user (sender & receiver) , and SMIME allows a group (or a business) & it's members / employees to communicate encryptedly.
When emails are encrypted with OpenPGP / PGP / GPG, then others in the middle of internet connection path, can only see encrypted / scrambled content which has random letters & numbers & symbols etc & not-meaningful message , so others cannot see actual content of email body , ( unless someone in middle of internet path have the key / cert to decrypt ).
When OpenPGP encryption mechanism is used, then email-server's admin, partners, sub-contractors, etc etc etc cannot (instantly) see email's content , even if two person used gmail / yahoo / hotmail / outlook / protonmail / on-premise / self-host based etc email services.
If weak strength OpenPGP / PGP / GPG encryption are used, then very powerful computers can find decrypt key & can decrypt & obtain actual message, not-instantly but after some time.
When SMIME based encryption is used, and if the email-server is located in a cloud or in a remote host server, then remote location's or cloud service provider's admins, partners, sub-contractors, etc, etc etc etc can view/access/copy emails.
When SMIME based encryption is used, and if the email-server is located in your own or in a very very very trustworthy person's premise , or on-premise , or self-hosted , then only you (or that trustworthy-person) can view/access emails , no one else can view/access.
Anything thats not in your own hand/home/control , is by definition , not-secure.
No matter how much sugar-coated words or carrot they hang in front of you or no matter how much they ridicule / contradict you.
Remote hosting aka CLOUD based service providers & their businesses & profits have ballooned & become filthy+dirty rich, abusive, manipulative, liars, etc, they even fund corrupt lecturers to lecture on how "secure" things are in CLOUD / remote hosting. Cloud/ remote hosting can give other/fast-sharing etc benefits, but not on real security. They invent things (and brainwashes all) to assist remote/cloud stuff further, but not assist to improve user's on-premise / self-hosted solutions.
Not only USA's 4th-Amendment, also worldwide, UN have setup clear agreements & rules, for all countries, by using UDHR (universal declaration of human rights) , where every member countries have signed to uphold those UDHR rules & agreements, which includes Privacy-Rights,
but biggest violator country(s), each have more power than UN itself.
A significant percent of ppl in World is operating willingly & unwillingly & coercively to participate in corrupt & harmful & human-rights violating activities.
https://www.un.org/en/universal-declaration-human-rights/
https://en.wikipedia.org/wiki/Fourth_Amendment_to_the_United_States_Constitution
https://www.aclu.org/united-states-bill-rights-first-10-amendments-constitution
https://www.law.cornell.edu/wex/fourth_amendment
https://www.britannica.com/topic/Fourth-Amendment
https://en.wikipedia.org/wiki/Spying_on_United_Nations_leaders_by_United_States_diplomats
We ware shirt, jacket, socks, shoes/sandels etc to protect us from harsh weather, thats what civilized person, culture or community do for safety & protection.
Encryption is the shirt/jacket/socks/shoe/sandel inside internet cyberworld / digital world to protect us from harsh things inside internet.
https://en.wikipedia.org/wiki/Encryption
If encryption(s) are broken easily or allowed to be broken by special-peoples (by using backdoors), then they will inject harmful data , conflicting data , crashing/collision/malfunction data inside vehicles safety, plane travel safety, financial transaction safety, health-care safety, etc etc etc when it will be necessary by corrupt group of people in govt to do so ... harmful or unethical hackers will find those backdoors & abuse ... & create massive loss for people's life & safety. This already happened, USA's NSA allowed their certain sub-contractors to leak their invented malware publicly, then those malware were abusively used (by harmful+unethical hackers) on other nations.
https://en.wikipedia.org/wiki/Equation_Group
https://en.wikipedia.org/wiki/Backdoor_(computing)
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