My mbsync setup

.mbsyncrc

IMAPAccount gmail-aaraines
Host imap.gmail.com
User aaraines@gmail.com
## Since mbsync doesn't have a way to pull in passwords from other
## locations, I pass this file through Text::Template via the below
## ttexpand program before invoking mbsync with something like
## `mbsync -c <(ttexpand <~/.mbsyncrc)`.
Pass {readrc '.auth.aaraines@gmail.com'}
UseIMAPS yes
## aptitude install ca-certificate ---v
CertificateFile /usr/share/ca-certificates/mozilla/Equifax_Secure_CA.crt

IMAPStore gmail-aaraines
Account gmail-aaraines

IMAPAccount local-aaraines
Host localhost
User aaraines
Pass imap
UseIMAPS no
RequireSSL no
UseTLSv1 no

IMAPStore local-aaraines
Account local-aaraines

Channel aaraines
Master :gmail-aaraines:
Slave :local-aaraines:
Patterns !* list.*
Create Slave
Expunge Slave
Sync Pull

ttexpand.pl

#!/usr/bin/env perl

# Filter stdin while executing embedded perl.

use Modern::Perl;
use Text::Template;
use File::Spec::Functions;

sub readrc {
  my $file = shift;
  my $s = Text::Template::_load_text(catfile($ENV{"HOME"}, $file));
  chomp $s;
  return $s;
}

my $tmpl =
  Text::Template->new(
     TYPE => 'FILEHANDLE', SOURCE => \*STDIN);

say $tmpl->fill_in();