您可以覆盖电子邮件验证程序的匹配器以允许空字符串：

Ext.define('my_model', {
    extend: 'Ext.data.Model',

    identifier: {
        type: 'sequential',
        seed: 1,
        increment: 1
    },

    fields: [{
        name: 'date',
        type: 'date'
    }, {
        name: 'msg',
        type: 'string',
    }, {
        name: 'email',
        type: 'string',
        allowBlank: true
    }],

    validators: {
        date: {
            type: 'presence'
        },
        msg: {
            type: 'length',
            min: 2
        },
        email: {
            type: 'email',
            // Override matcher to allow empty string
            matcher: /^$|^(")?(?:[^\."])(?:(?:[\.])?(?:[\w\-!#$%&'*+\/=?\^_`{|}~]))*\1@(\w[\-\w]*\.){1,5}([A-Za-z]){2,6}$/
        }
    }
});

Ext.application({
    name: 'Fiddle',

    launch: function () {
        var myModel = Ext.create('my_model', {
            date: new Date(),
            msg: 'Some Message',
            //email: 'mustermann@gmail.com',
            email: '',
        });
        console.log(myModel.isValid());
    }
});