While there's been a lot of attention on cases where AI fails quite poorly (such as anything requires factual information), it is actually very good in specific use cases.

I personally find it very useful for answering NP-hard-like questions (Hard to find an answer to, easy to verify answer is correct), such as when I have something on the tip of my tongue or looking for a specific term/word.

It's also fairly good at summarizing, as well as generating text. You may not want to send the e-mail as is, but it can be a good starting point for drafting an email or message.

These seem like specific value add, especially in the context of an email frontend.