This is a new stable release. There is an incompatibility that may be worth an einfo. From the release notes: Postfix no longer appends the system-supplied default CA certificates to the lists specified with *_tls_CAfile or with *_tls_CApath. This prevents third-party certificates from getting mail relay permission with the permit_tls_all_clientcerts feature. Unfortunately this change may cause compatibility problems when configurations rely on certificate verification for other purposes. Specify "tls_append_default_CA = yes" for backwards compatibility.
Added to CVS.