As several others here have written, the vast majority of people don't care about their (or your) privacy: so most of our contacts are just more holes in a very leaky boat.
When it comes to email, I'm going to go out on a limb and say people should _never_ trust it for sensitive communications. Message content itself can be protected by pgp encryption (if people would bother to use it), but there's no watertight way to consistently avoid the kind of relationship mapping that nation states and transnational corporations have been doing for the last two decades. That game is already over, and Big Brother won -- no matter who you use for email.
* https://articles.59.ca/doku.php?id=em:anonemail
Ultimately, for the strongest privacy protection you need to go to something offline, like email:
* https://articles.59.ca/doku.php?id=em:emailvsim
Obviously not everyone needs the highest level of protection, but the fact still needs to be acknowledged.
The message might be encrypted, but if they get to the other guy and offer him a sweet enough deal, there is no protection. There are two copies of the content out there, if it is that serious, why leave the papertrail.
People like to believe they are subverting the CIA snooping on all their very important 'activism', but in reality the most they are doing is opting out of google using their emails to market them shit they were never going to buy in the first place.
