@Pablito Thanks!
Yes, Protonmail tends to be the most widely recommended... which is what would draw caution from me. If it was not linked to CERN etc. I would not have hesitation. I've had a Protonmail account for a year now, but am planning to decouple completely from Google soon.
Tutanota is another well known highly used platform... it also has desktop and Linux Apps along with the normal android/apple.
Note the 666 is their logo... says it all. Expansive hadron collider tied into the apex of the world's scientific endeavor.
@wildgoose What is CERN? Is ProtonMail linked to google?