I just wanted to say something about MLCers & anger in general. I can't remember what you said about your H's background, but if your H was like most of these MLCers, he was not "allowed" to be angry, even when his childhood gave him reasons to be.
My H, for example, had a mother who was the "angry one" in the house, and H felt he was the main target of her outbursts. I'm sure, in the way children have, that he felt guilty for "causing" such explosive anger. He also feared being angry himself. As a result, he learned to be a "nice guy," to suppress his anger, to "take" more from others than he should. So, for example, if his boss wanted him to work overtime or all weekend with no recompense, he didn't know how to say no (because he was afraid of making his boss angry at him) AND he'd suppress his own anger at being treated unfairly by being robbed of his down time. In other words, his fear of anger had prevented him from growing up properly.
Was your H somewhat like this?
Because if he was, when the MLCer spews or sends vitriolic emails, try to think of him as learning how to try on anger. He was not modelled "appropriate anger" as a child, so he's going to get it very wrong at first. He's going to try thunderclaps from the heavens, like his parent showed, at first, and he's going to have tantrums like a normal toddler would have been allowed to have, with a different parent, and he's going to try sneering, mean anger like some of the kids at school, and he's going to have those I-don't-understand-what's-happening-to-me adolescent rages ... and in the end, if all goes well, he's going to learn to understand, control and use his anger quietly and effectively.
Now, while he's getting on with his task, you can get on with yours, giving his spews only the minimal attention they deserve.