I think OS X Mail.app for Yosemite is a pretty good Gmail client. The one big problem is that one must download the entire archive, though there is an option to omit automatic attachment download. That’s fine for my primary machine, but I don’t want to burden my 256GB SSD with 20+ GB of Gmail archive. So I went looking for a Gmail client.
I used Sparrow years ago and liked most of it — except the obligatory threading and conversation views. If an app is going to do that, it has to let me quickly delete all the emails I no longer care about. Sparrow didn’t.
Sparrow’s gone of course. More recently i used Airmail with some success, so I tried Airmail 2. That was … frustrating. I ran into multiple bugs and UI issues when I migrated from Airmail 1, so I tried again with a fresh start. This time while sending an email I got an authentication failure. No problem — I quit and fixed the error (I think). I then went looking for the stalled email and … it was nowhere to be found.
I deleted Airmail 2. (That was money wasted.) I then tried Mailbox.app — forever in beta, mostly abandoned, and you can’t delete individual messages, you can only delete an entire conversation. Deleted Mailbox.app. Next up - Postbox.
Postbox doesn’t support Google OAUTH2. I read the documentation on enabling “Access for less secure apps” and … I deleted Postbox.
So I’m back to Mail.app. I disabled automatic download of attachments in preferences, but I guess I’ll just sacrifice the disk storage. I considered enabling Google’s IMAP folder message visibility limits, but of course that would apply to my server too. I think in past Mail.app had some control over message downloads, but that’s gone now.
The bright side is I don’t mind Mail.app. Just hate the lose the storage...
Update 7/18/15: With ‘automatically download attachments’ off, selecting Inbox and choosing Account Info from the Context menu tells me that 80,309 messages are using 4.35GB. I can live with that.