This is going to be long, sorry. I put my SIL on email block last year, and have no regrets whatsoever.
I hate to bore you with backstory, but . . . my mother is an N. I have always been the target, Sister has gotten some of it, while Brother has been placed on a pedestal, the male heir, center of M's universe. While S and I have both struggled through life, B got private schooling, numerous free cars (all the ones he crashed were promptly replaced), ten years of free college, a beautiful apartment, etc. He lived an all expense paid life, which got even better once he got married. He was given a house, a European honeymoon, and every year, lavish Christmas gifts. The worst part, he married a girl just like dear old Mum . . . an N.
SIL is a real piece of work . . . unbelievably superficial, and very proud of the fact that she has married a meal ticket. She doesn't work, just leaches off the parents. She has tried very hard to replace S and I as top "daughter," secure her place in the will, etc. Since she married the favorite child, it hasn't been a problem for her.
Last year, S and I finally reached our limit with M's Christmas celebrations (we are all in our forties, yet M insists on continuing the type of Christmas we had as young children, trying to maintain control over us). We got sick of watching B and SIL being treated like royalty, so neither of us showed up for last year's shindig. This sent M into a rage. She apparently vented to SIL, her only guest. M is a pathological liar, so all the info SIL got was, well, a lie.
A week after Christmas, S and I both received a two-page email tirade from SIL, telling us how much she hated us, chastising us for mistreating our "wonderful" mother, berating our choices in life, going into details about our careers and finances, and talking about some of our childhood experiences (personal information that could only have come from M). I mean, she did NOT mince words. Three hours later came a second email. I thought that perhaps she had time to think about it and was sending an apology. WRONG! Instead, I got this:
"Oh, and re: your request to get the receipts for your Christmas gifts so you can return them- considering the ugly, cheap, lame-ass gifts Paul and I have accepted with grace and thanks from you over the years, you can forget it. Here's a plan - if you're having so much trouble with your 'expenses', why don't you try not spending all your money on Beanie Babies and dolls and crap, and start managing and investing like normal adults. And in the future, should either of you have anything to say to me - contact me personally. I'm not going to be taking any more of your snotty demands from your mother. If you don't have the guts to deal with me instead of using your mom as a messenger, then you don't deserve any more of my time or attention."
First off, I never wanted her time or attention. Second, I never asked to return her gifts, because she's never bought me any gifts. The best I've ever gotten from her is free promotional stuff that came from B's office . . . socks with the company logo on it, etc. I have, however, always bought very nice gifts for the two of THEM, usually high denomination gift cards, and nothing that would be considered cheap, lame, or ugly. Anyway, that final comment about my gifts cut to the bone. Even if my gifts HAD been cheap and ugly, it's the thought that counts, you know. Or so I thought. This was intentionally cruel. Just evil.
Needless to say, that afternoon I put her on email filter. I know that any emails that she's tried to send were probably equally cruel, so I feel that I did the right thing in sparing myself a lot of hurt. It's not like I missed an apology. Surely that will never come.
Geez . . . as if it weren't bad enough having a mother who is an N. I'm also, BTW, considering placing M on email block. This one is going to be harder though. Like others have mentioned, I'm not yet at the point to end ALL contact with her. But as far as SIL is concerned, yes, all doors are now closed.
