Updating Apple Mail from Mt Lion to Sierra - should I upgrade Mail or re-download everything

[minvoyager]

I run Gmail with ... gulp ... Mountain Lion, and am going to transition to Sierra.

My question is about updating Apple Mail running Gmail: which will provide me with the most trouble-free installation, (i) upgrading Mountain Lion to Sierra such that the Apple Mail database will be automatically converted, or (ii) do a fresh download of my entire Gmail IMAP data, which is around 12GB over several accounts, which is why I'd prefer not to do a fresh download.

FYI, I did a clean install of Sierra. For the Apple Mail, if I were to just convert it, I would install Mountain Lion in a VMWare Fusion, update the VM to Sierra, and then copy the converted V4 files across.

I'd like to hear people's experiences of upgrading to Sierra from much earlier versions of OSX (such as Mountain Lion), and whether those upgrades caused problems with their Sierra Mail.

I realise that the absolute, most-pristine approach would be to download all the mails again, but that would take ages and ages.

 

[minvoyager]

Ok, here's an update so others can benefit from my wanderings.

The take-home message is that it's better to just re-download the entire 25+GB of IMAP data, rather than converting it.

I tried this: in a VMWare Fusion virtual machine, I started with a clean install of Mountain Lion, installed with my Apple Mail. Then I went, step by step, upgrading to Mavericks, to Yosemite, El Capitan. At the point where the database went from V2 to V3, the upgrade and conversion of Apple Mail totally messed up. One account, and its folders, just disappeared as a result of Apple's conversion.

I sought the advice of a company that does email conversions, and they were of the view that Apple's own conversion was quite flaky, which was what I found out too.

I realise it is a pain to re-download 25+GM of IMAP, but it just has to be done.

And this time, I'm not going to use Apple Mail. I don't want to go through this process all over again when every 12 months they change the system.

I'm going to use Postbox for Mac which uses standard Mailbox formats, so I can, later on, simply copy the standard mailbox over to the new system.

Why is Apple so insistent on changing their operating system every year. If the upgraded benefits were significant, then, fine - but the updated features are not useful to me. All the additional features that Apple justifies in having a completely new system every 12 months - other developers can deliver to me in standalone apps. So Apple just shafts us with a new operating system every 12 months just for marketing purposes.

Just look at the fact that software developers have to put out new versions of their software -- and charging us money for it -- just to keep up with Apple's 12 month operating system cycle. And what for? Why can't they do what Microsoft does, and maintain some consistency over a few years.

The only reason I stay with Apple is because I value beauty of design, both in software and hardware, and I just like Apple's machines. I'm a glutton for punishment.