[MlMt] Heads up for insanely early adopters: macOS Sierra and MailMate

[Scott A. McIntyre]

Hi all,

After a glass of wine it seemed like a fantastic idea to update my iMac 
to macOS Sierra Beta 1.  Like all great ideas which are fuelled by 
fermented and/or distilled beverages, there have been moments of regret.

MailMate *mostly* works, but, in case any of you were thinking of going 
this route, learn from my pain:

0)  macOS Sierra is towards the Alpha side of Beta, don't expect things 
to work well, be happy anything works at all.  Don't harass developers 
for support yet.

1)  The Keychain seems to have been seriously overhauled, or, broken, 
depending upon how you look at it.  This impacted MailMate for all 
stored credentials and having to re-enter them.  Not a big deal, but, 
time consuming.

2)  I use a private TLS protected mail server for my outgoing mail, with 
my own self-signed certificate protecting it.  This caused MailMate to 
crash hard on Sierra.  The fix was to use openssl to grab the PEM and 
import it into the Keychain with full Trust.  No more MailMate crashing 
on sending SMTP.

3)  MailMate can not see your Contacts/Address Book.  This will be a 
deal blocker for most people - and indeed, it's been the biggest 
headache here.  It can see its own internal list of previous recipients, 
which is good, but, that's it.  I tried resetting the Address Book with 
tccutil, and whilst MailMate prompted for access, obviously something 
has changed in the format and nothing is actually seen (including in the 
Address panel in MailMate).

Other than that, MailMate seems to be working okay.

This is just a heads up for others, I don't expect Benny to make any 
changes to support Sierra for many months to come.

Regards,

Scott