"I am not at all worried about you reading any of my emails. I am not doing anything to put our marriage at risk. you are welcome to review any email I have sent or received on my PC. I have no secrets from you and I won't have any. I made a commitment to you when I married you. Keeping secrets from your partner is disrespectful to say the least - I would never do that to you."
Implied here is that your WIFE was the one being disrespectful by cheating.
Its classic double standard. She can disrespect you by cheating and lying, but if you read her email suddenly respect is a standard you both have to follow?
You don't demand respect, you EARN it. And she's been shortchanging you of late and in my opinion has given you reasonable cause to check up on her communication with OM.
Do NOT argue this case with her. Just give her the quote I put up there and stop talking. Do NOT agree or apologize to any argument she makes.
Just repeat your position.
You have no secrets from her. Secrets make you sick and erode a marriage into nothing. Challenge her to open your email and for her to read whatever she likes.
Tell her your commitment to her is 100% and you have no secrets, but she can check up on your mail at any time if she's at all worried about you.
THIS is YOU setting an example of an HONEST household and an HONEST marriage.
Don't attack what SHE's doing see... just SHOW an EXAMPLE of how an ADULT uses a computer and let her do the math on her own.. she will figure it out.
