
However, “All Mail” is confusing in Mail a Mac or an iPhone, and its presence causes duplicate copies of everything to be downloaded. “All Mail” sort of makes sense when you’re on Gmail in a web browser, and you work with labels applied to messages, rather than messages within folders. It’s instead in the Gmail “All Mail” folder, along with every single message that you send or receive, regardless of what other folders they may (or may not) appear to be in. And if you simply tap it once, which is easy to do unintentionally, the message vanishes from whatever folder you’re looking at it in, without any confirmation. What this means is that when you’re looking at a message, there’s an “archive” icon at the bottom of your screen where the trash usually is. There’s also a general Mail option to Ask Before Deleting, which is off by default.

Here’s what’s usually happening: by default, when you add a Gmail account to an iPhone or iPad, there’s an option to “Archive” messages rather than put them in the trash, and it’s enabled by default, which you’d never know because iOS doesn’t show it to you unless you go back and look at the account settings after you add it.

Many of our clients who interact exclusively with their Gmail or Google Apps accounts through their Macs and iPhones have reported messages “disappearing”. This is the possible first in a series of posts on Gmail’s idiosyncratic behaviors with Mail on Macs, iPhones and iPads.
