Consider the following sentence:
I haven't heard from either you, (n)or her.
If I started my sentence with "I have heard from neither you" then the "nor" would follow. My doubts stem from the fact that I'm using negation (which suggests "nor") but I'm also using "not" ("have not") and "either" in the first part of the sentence which suggests "or" in the second part.
So which one is it?