Robert,

Thank you for pointing out that `org-link-mailto-program' should not be 
recommended in FAQ any more.

I prepared an alternative patch that recommends to customize Emacs 
variables at first. I hope, an example is safer now, however I can not 
test it on MacOS. Could you, please, review the patch, since I may miss 
something important from your point of view?

On 07/01/2022 18:03, Max Nikulin wrote:
> On 07/01/2022 01:34, Robert Goldman wrote:
>>
>> +You can also change the function used to a different one.  For
>> +example, the following function (on MacOS) opens =mailto:= links in
>> +the =MailMate= program:

I am unsure if MailMate is acceptable since it is a proprietary 
application. Org is a part of *GNU* Emacs, so it may be better to 
mention some free mail user agent.

>> +#+begin_src elisp
>> +("mailto" :follow
>      ^
> It seems, `org-link-set-parameters' is missed.

I am sorry, I missed that you suggested to customize the 
`org-link-parameters' variable, so function call is not necessary here.