How delete mail from 1 of 3 PCs on same wifi?


New Email
I have three laptops on home wifi. Win. 7 on all 3, and use Yahoo mail (the new one) on all three from time to time. All three maintain the same emails stored in various folders. Delete one on #2, it is deleted also on #1 and #3, and vice versa. I am donating one to a child, and I have it all ready, except that I do not know how to delete my email files, some rather personal, from only the laptop I am donating, without their going away on the 2 I am keeping.

Any help out there for this computer-illiterate?

Tks much,