Is divorce via email considered valid, and is a signed document required to prove it? And is it permissible for the remaining two divorces to occur immediately?

Divorce occurs simply by utterance or writing. A husband's divorce of his wife via email is valid if it is proven that the sender is the husband or his agent and he admits to it. However, if this is not proven and the husband does not acknowledge it, then the message is not considered, and the divorce does not occur. The 'iddah (definition) (waiting period) begins from the moment the divorce is pronounced or the message is written.

It is not possible to issue two divorces at once; divorce occurs one time after another, and each time has its own 'iddah. If the first divorce was counted, and the husband takes you back during the 'iddah, then each divorce is counted. If he does not take you back until the 'iddah ends, then you are irrevocably separated from him, and it is not permissible for him to return to you except with a new contract and dower.