The search function is non-existent.  It's completely unusable.  I can't find an email by a person's name, and searching for anything short of the full domain results in nothing.  I have thousands of emails and can never find anything.  I'll search an invoice number, and the invoice number will be in the subject.  Search returns empty.  I'll search a name.  Search returns empty.  I literally can't use this service anymore, I can't deal with this.  I see years and years of the same issues listed in these threads going back 8 years.  I know nothing about how to make an internal search engine, but there's no way it's impossible to return something as simple as partial matches if I type FIRSTNAME rather than FIRSTNAME.LASTNAME@DOMAIN.COM.  This is insane.  It's not a new issue I've had, it's always been like this.  I'm just at a breaking point being unable to ever find things in my inboxes and having to spend hours on simple email tasks.  I'm going to have to migrate the whole business to another platform and I really don't feel like it.