Setting aside the question of whether using an e-mail service with a company that trolls e-mails for keywords in order to target you for advertising could violate client confidentiality, you might consider whether a now non-beta feature is exactly the tool you've been waiting for.
Per Gizmodo, Gmail has officially added a way for you to unsend emails that were perhaps poorly worded, had confidential information attached, or otherwise need to be deleted promptly (as though you can really delete electronic files . . . ha!).
So how do you enable Gmail’s undo feature? Go to the little cog icon in the upper righthand corner and select “Settings.” About a third of the way down the page you’ll see the “Undo Send” section. You can choose between 5, 10, 20 and 30 second windows of unsendability. Make sure you hit “Save Changes” at the bottom and you’re all set.For those of you wondering about the professional ethics implications of using Gmail for confidential business, check out these articles: