/etc/dovecot/dovecot.conf template (70smtpauth): disable GSSAPI authentication method if samba role is not ADS. Refs #1747
/etc/postfix/{main,master}.cf templates: "legacy" SubmissionPolicyType. Refs #1818
nethserver-mail-server-migrate action: enable legacy SubmissionPolicyType. Refs #1818
/etc/dovecot/dovecot.conf template (60lmtp): enabled imapflags obsolete sieve extnsion. Fixes #1816