For years now I've had Google Apps for one reason or another. What started out as a employer's choice in one spot and merged into being easier than managing my own servers lead me down that path. There are plenty of reasons that I'll be migrating away from this solution soon but for now it's the devil I know and have time to feed. I'll save the rant as to how many different ways gmail is really broken for another time.
Until the release of OS X Mavericks there was an uneasy truce between Mail.app and Gmail. You simply did a few things, well a bunch of few things, but one time setup and it was done. Then along came Mavericks and there was pain. A few changes and things were ok again, assuming you had the time and bandwidth to let your massive collection of email download. The truce was uneasy but it continued to work. Then last week Apple released a fix to help Mail.app work better with gmail. And that's when things stopped working. At least for me and a collection of others who could no longer get mail in the Inbox.
New messages would be dutifully added to the All Mail aka Archive, but would never appear in the Inbox on Mail.app no matter what. For several days I've been keeping an eye on my still-wroking iOS mailboxes and then going to read messages as I saw them come in. Today I finally bit the bullet and deleted my gmail account locally and re-added it. And there, for a fleeting moment, were my Inbox messages. Tantalizingly the Inbox went from zero messages to 45. The window open just behind my browser window was filled with bullets announcing new messages. And then they were gone. Back to the way it had been before. Messages that had been in the inbox before the update to Mail.app were there and nothing else.
So what made these messages appear and disappear? There are three plugins I use with mail all the time. Two of them are things I can't live without that make me a committed user of Mail.app. One is the excellent GPG Tools for sending email securely. The other is InDev's Mail Act-On which provides for the application of mail rules at times other than just incoming or outgoing. I want to file some things after I've seen them and Mail Act-On provides the tools for just that. The third plugin, mostly because I picked it up at the same time is InDev's MailTags.
To be perfectly honest I've had MailTags for a long time but never been a heavy user of it. Perhaps because the lack of support in Gmail for it means my tags couldn't be synced from computer to computer. Or some other reason I'm not sure. But it's been there and I keep updating it and use it from time to time. It turns out, however, in this case that MailTags was the culprit. A quick trip to the library mail folder in my user's home directory and disable the bundle and sure enough things are back to working. Or at least working as close to the gmail facsimile of working.
Update: As is too often the case I could have sworn I had the latest version before losing what's left of my hair over this. Well I did have it at one point but the fine folks at InDev have already issued a fix to the problem per this message on Twitter. I haven't verified that yet since my setup doesn't really need MailTags but it's great to know they're on top of it!