Hi luizka85great-gm,
It's important you have the correct email in order to prevent any delays with receiving update emails. I'd be happy to steer you in the right direction with this.
Just in case you're using QuickBooks Canada, I recommend checking out this article here. The article is similar to the one mentioned above except this one is a Canadian based article. If you're having issues with saving the new email, I suggest updating the email using a private/incognito browser window. Doing this by-passes any cache/cookie related issues which may be affecting your browser. I also recommend clearing cache and cookies on your browser. Here's an article which shows you how: Clear cache and cookies to fix issues when using QuickBooks.
In case you have other questions, feel free to contact our support team using this link here. Otherwise, enjoy the rest of your week! :)