@Interrobanger
The fundamental question is whether the statements have caused serious harm to the OP's reputation. If they have, she has a case
That’s what I said? She has to show a loss. Otherwise everyone could sue anyone who talks shit about them.
The problem with paraphrasing 'serious harm' to reputation as 'loss' is that it isn't accurate. Most lay people would understand loss to mean financial loss - which is not necessary to show for an individual (as distince from a profit trading body).
Serious harm to reputation CAN be shown by financial loss in some cases but actual loss in a financial sense isn't necessary. What you need to show is serious harm to reputation which can be contextual in nuanced cases.
Eg. accusing someone of murder will in most cases qualify as serious harm but it may not do - if it was only published to ( in the sense of read by or disclosed to) one person who didn't believe it. There is no real harm because only one person read it and they didn't believe it anyway. On the other hand, sending an email round the whole of your parents year group saying that you can't be trusted to look after children because you are a drunk (Whilst less serious than an allegation of murder) may cause more damage to your reputation day to day than the first example.
@Dataretrieval starting with an SAR is a good starting point. The redactions will probably be the names/personal data (email addresss/phone numbers) of people mentioned other than you.
Obviously you found out about this some way - so another way of trying to get an copy of it is to approach the person/people who told you about it and ask if they will give you a copy.
How do you know about this email? What exactly do you know? And have you got corroboration? (One person told you alone or more than one independently).
If you have no joy with either the SAR or asking those who you think received it for a copy, in some circumstances you can apply to the court for pre-action disclosure but in libel cases this is very problematic. 'Fishing' for possible defamation is not really permitted so you'd need to show (by witnesses ideally giving statements) that you had been defamed, you knew it but you couldn't get a copy. If you need to make this sort of application, you would need to see a lawyer to advise you about whether it would be possible in your case.
No, harassment is a criminal offence. Libel is handled in the civil courts.
This is misleading. Harassment is both criminal and civil. You can bring a private harassment claim against someone harassing you.
It does sometimes happen that you have both a harassment claim together with a libel claim but usually if there is also a harassment claim, you may not need a libel claim. This can be a tactical question sometimes driven by costs issues. It depends what the biggest problem is - whether it is the harassment (repeated actions disrupting your life) or if it is the libel (a statement made about you that has seriously damaged your reputation and that you want to be made absolutely clear publicly that is not true) and whether your key objective is to get money or to get an injunction (order stopping it).
For harassment you need two or more harassing actions that constitute a course of conduct. One email is unlikely to be enough as it would count as one action. I suppose it could be if the same thing was sent sequentially and repeatedly - but you'd expect one email to be sent to everyone in one go.
The other thing to remember is that generally the limitation period for a libel claim is 1 year from the date of publication. This means that in most cases (unless there are exceptional circumstances governed by a statute) you need to issue a legal claim before a year has gone by from the date the libel was published (in the sense as indicated above - ie. disclosed to others).
All of the above comes with a chunky caveat that as always, you can never get proper legal advice on an anonymous forum because it is always fact dependent. Best advice is to take everything you read here with a healthy dose of salt and a skeptical eye and get formal paid for legal advice.