[MlMt] MM as default mail client ?

[Bill Cole]

On 8 Nov 2012, at 16:28, John Roberts wrote:

> HI,
>
> This does not work with all applications. Emailing photos from 
> Aperture, for example, opens the Apple Mail.app. is there a way to set 
> MailMate as the default mail client for all applications?

No, because the scope of the public standardized interface for driving a 
mail client on MacOS is extremely narrow, consisting only of setting an 
app as the default handler for "mailto:" URLs and as the default opener 
of various mail-specific file types. Because the mailto: scheme can't 
handle complex or large messages, most apps that need to do anything 
interesting with email either implement what they need internally 
(perilous) or use Mail.app specifically, which has a rich published 
interface accessible via AppleEvents and OSA. Historically there have 
been some cases (e.g. iCal through Leopard) where individuals apps have 
implemented their handling of Mail.app via external AppleScripts, making 
it possible in principle for the user to replace the interface with a 
script driving a different mail client, but that was pretty clunky in 
practice.

What would be needed for the ability to swap in another mail client for 
Mail.app universally would be:

1. Apple would need to license the OSA suite definition used in Mail.app 
so that developers could reproduce it functionally in their own mail 
clients.
2. Developers would need to actually implement the defined interfaces 
for their mail clients.
3. Applications currently using Mail.app explicitly would need to change 
their code to use the default mail client (i.e. mailto: handler) 
instead.

I would not expect this to happen within the foreseeable future.