I believe its always okay.
I also believe in transparency in marriage... So I'm never on the "Gasp! You found out your husband is selling arms to soviets by looking in HIS _____?!? How DARE you?!?"
Um.
Arms dealing totally ignored???
Wha?
Adultery.
Lying (telling others untrue things about your marriage or telling you untrue things and telling others the truth)
Gambling
Addictions
Illegal activity
Ad naseam
Vs.
Reading someone else's mail.
Yeah.
I just don't see the comparison.
I THINK it might be a byproduct of
- Longer dating/courting norms (because the trust is not implicit, yet... Nor does spousal privilege apply)
- Decline of literacy (letters were once upon an Artform, and were read out loud before being mailed / then to everyone in the house... Excepting live letters & business letters)
- Newness of electronic conversation means that we're INVENTING the social norms surrounding electronic conversation as we go along.
HOWEVER... Sometimes the "delve deeper" IS the insecurity, stalkerishmess of a particular post. There's a BIG difference between transparency & total lack of trust. The first is normal/healthy, the second is not. When someone is reading every email/ text/ bill/ letter, has VARs, GPS tracking, Spanish inquisitions...
... Its a big deal.
Pretty normal in rebuilding trust following total betrayal, but if no betrayal is present? That's paranoid, untrusting, hyper controlling, hot mess. That needs help