Shopify holding funds until account details are updated

What you're describing seems to be a spam email sent to you by a hacker. If you follow the links in that email or answer the hacker, they will probably be able to log into your Shopify account and cause a lot of damage. First, you should verify that this email is indeed fake and report it both in your email app and to Shopify. Also, use a different browser to log into your Shopify account and make sure everything is in order. If you have already given this spammer any details about your account, you should change your login credentials immediately and contact Shopify to make sure your account is safe. Here's a more detailed post about how to keep your Shopify seller account safe: https://keepshoppers.com/blog/Preventing-your-Shopify-account-from-being-hacked