1. At the outset, once fair procedures are followed in voting out a director from their position as director, then the law does not intervene. The members of a company are allowed to choose whoever they wish as a director based upon whatever prejudice they want. The law does not intervene in this area. So it makes no difference that the grounds may be defamatory or abusive or ill founded. A private company limited by guarantee is able to carry on its affairs so long as it adheres to its written Articles & memorandum. So the issue of contesting your removal does not arise unless you can show the relevant company rules were not followed or proper company procedures were abused in some manner. This is why you rarely, if ever, see the removal of a director successfully challenged in court. Once the members vote, a court cannot set aside this vote and the decision reached in accordance with it. YOu are much better off seek to influence the members in how they vote than seek to challenge it legally.
2. As regards any emails which might be defamatory or abusive, you can issue legal proceedings if the emails were published to a third party on the basis they were defamatory. But if the emails were merely between the two of you, there is no publication and so no defamation action will arise. As regards abusive emails, the law does not provide a remedy. You can take whatever action you wish in relation to it, but the law does not require people to be polite to one another. Finally, be aware that the law does not require that the grounds for your removal be provided to you in advance of any meeting to remove you. So it is not a breach of company law that any allegations made against you were made in secret. A company is a private body and the law does not intervene in its internal management or police the decisions made by it.