Which is why it is so odd that Mac Mail continues to be so utterly rubbish.
The service should be a core component of of Apple's OS, particularly if it really wants to continue its upward trajectory in a the business space. An increasing number of businesses are using Mac, but Microsoft remains dominant in the business space, with Outlook the major email platform. For Apple to really compete on that turf it needs to up its game with Mail when Yosemite is finally released, because, in it's current form, it simply is still not a reliable enough product.
This is particularly true when used in conjunction with Gmail, a service used by millions worldwide (including businesses via Google Apps,) as their email provider, and theere were notorious problems with Mail in Mavericks when the upgraged launched. Apple improved but still doesn't seem to have quite fixed, and I had complaints long before the current issues.
As with an unconvincing lover, I have a rather on-off relationship with Mail. I keep giving it another chance, thinking its changed, but ultimately it keeps letting me down. During the many years of the fraught relationship, I've had smtp server settings drop out for no obvious reason so I can't send emails until I delete and add the account again, and emails with images attached disappear off into cyberspace, never to be seen by the recipient. The latest issue is saving every draft to the Gmail server automatically, and resetting that option every time I turn it off, or just ignoring the instruction all together. This means that a single email can produce multiple drafts clogging up my phone and account.
It really isn't good enough for such a vital tool. You need total reliability with an email client, whether you're organising a party or running business. So, just like that lover that keeps on letting you down, I've come to the conclusion that Mail just is never going to be what I want it to be. Ultimately my trust has been too damaged, and I have to walk away and look around for alternatives. As with looking for a new partner there are many new to choose from.
Spurned as I was, I started looking for a plain and simple alternative – native Gmail on the web. This obviously works well, and syncs easily with a phone via IMAP, but I hate having to always have the tab open. This is particularly annoying if I have GChat running in Messages as it appears in the web browser too and I get the same instant messages multiple times.
There is also Sparrow, which is designed specifically for iPhone and Mac, and many people rate very highly. It costs $9.99, which really isn't a lot, but seems a bit unnecessary when there are various very good free options. The same goes for the Gmail app in the App store, which is £6.99 in the UK store.
I've also tried the the cheaper alternative of App for Gmail. It adds a tab in the toolbar, and gives the option of flipping between mobile and desktop versions of the app. It works quite well for sending basic email, but is clunky and not good at sending attachments.
So at the moment I'm with Thunderbird, which is an email product from Mozilla. It's free, simple, and does exactly what I want. (Focus, I'm talking about email clients, not lovers now.)
Like Mac Mail, Thunderbird has the options for pop up notifications which integrate well with Mavericks. It also allows you connect various chat accounts, such as Facebook, GoogleTalk, or IRC. However, it's not as user friendly as Messages, which is obviously a default app in Mavericks anyway. There is a Thunderbird iOs app too if you want to use the same service across all your devices.
Another good free option is the increasing popular Mailbox. It works great on phones at the moment, allowing you to swipe away emails like rejected prospects on Tinder. It also allows you to set times for email you might want to reappear, and remembers you choices for when similar emails are sent to you aggain. A beta for Mac is being release shortly too, and is definitely worth looking out for.
I am sure as Yosemite moves from betal to public release Apple will try and improve not just the problems with Gmail, but with Mail as a whole. However, there are now almost no advantages that Apple's in-house version has over the alternatives. The only one I can think of is easy integration of events and invites between Mail and iCal, but there are easy ways around that (it's called copy & paste, or Google Calender…) Email, if nothing else, has to be reliable, and time and again the Apple's tool has proven not to be.
I'll have to see if Mail win me back once again, but for now, I'm quite with Thunderbird.