Done Being Nice *RANT*

Sarah
My fiancé doesn't get along with the wife of his mom's brother. He has no relationship with her. Nor do I. She is a selfish, terrible person who thinks only of herself. She throws around false accusations and always has to create drama for attention. She sent my fiancé's mom a horrible email in 2015 about what a bad mother she was for not paying for her daughter's second wedding (to be fair, their mom offered help but his sister said she was set and had everything). This same aunt only invited my fiancé and his brother to her house when they were kids for them to do the yard work her husband didn't want to do.
We didn't want to invite his aunt to our wedding this year. Invites went out, and his brother accidentally mentioned it to their aunt. She threw a shitfit about not being invited, so we sent them one with a note of apology and hopes that they could make it.
His aunt sent us back a long, scathing email about how we're terrible people, we're selfish and just invited them for money. That all my fiancé ever did was take from them and not give back. That I am rude and inconsiderate and play favorites because our venue is an old house, so there isn't enough room for everyone to sit during the ceremony, and her husband wasn't mentioned as one of the people having a seat.
In essence, we could go fuck ourselves.
We did email her back, and simply told her that this is why she didn't receive an invite initially, because she's so toxic and negative. My fiancé said he doesn't appreciate what she said about me, that all she had said was lies and that they are no longer welcome to our day; if they show up, they will not be allowed in. 
My apologies for the long rant, but this is a reason why you should go with your gut when doing your guest list. Don't invite people just because they guilt you.