Скрываем часть строки от спама...

HTML

<div class="my_style">
    <p class="mb-0 font-weight-bold">Email</p>
    <span class="email">0120912@mail.ru</span> <span class="email_active show">Скрыть</span>
</div>

JQ

$(function () {
    let holder = $('.email'),
        button = $('.email_active'),
        number = holder.text(),
        symbolsForHide = 7,
        show = () => {
            holder.text(number)
            button.removeClass('show').text('Скрыть')
        },
        hide = () => {
            holder.text(number.replace(new RegExp('(.+).{' + symbolsForHide + '}$'), "$1" + 'x'.repeat(symbolsForHide)))
            button.addClass('show').text('Показать')
        }
    button.click(function () {
        if ($(this).hasClass('show')) show()
        else hide()
    })
    hide()
})