I've rolled out new metapackages for Debian and Ubuntu. These packages specify the dependencies when installing the Virtualmin stack on Debian or Ubuntu.
Changes since the 6.0.7/6.0.8 release:
This won't make any difference for existing systems, generally speaking, though it will install Dovecot and SASL if they aren't already installed. If you want to use them, you'll still need to configure them with
virtualmin config-system --include Postfix SASL Dovecot.
Let me know if you run into any problems.