If you'd like to do an email too, please write in your own words for more impact - I'm not trying to present this as any kind of template!
Each email had a different personalised intro line, and here is the rest of my text:
"Women do not 'want a roll back of trans rights'. We want to protect existing rights to male-free space.
I am writing as a victim of a man who had got into women's showers.
Most crime, including sexual offending, is committed by members of the male sex, in mixed sex space.
So the Equality Act allows spaces free from the male sex for the safety of women and girls.
Toilets, changing rooms, locker rooms, prisons, refuges, showers, dormitories, tents - these are spaces women are vulnerable.
Self ID would allow any man to go into our spaces unchallenged, simply by claiming he is female, and nothing could be done about it.
The likely outcome is that predatory men will then use this loophole, causing more suspicion to fall on trans women's intentions.
The answer is not Self ID, but Third Space - retaining men's facilities and women's facilities and adding a third mixed space, that those who cannot or will not use their own can use instead.
Safe private space, comfort and dignity for all.
Thankyou"