Enable configurarion of header checks

templates/postfix/conf.d/header_checks.j2

@@ -0,0 +1,16 @@
+# Managed by Ansible
+
+/^Content-(Disposition|Type).*name\s*=\s*"?([^;]*(\.|=2E)(
+  ade|adp|asp|bas|bat|chm|cmd|com|cpl|dll|exe|
+  hlp|ht[at]|
+  inf|ins|isp|js|jse?|lnk|md[betw]|ms[cipt]|nws|
+  \{[[:xdigit:]]{8}(?:-[[:xdigit:]]{4}){3}-[[:xdigit:]]{12}\}|
+  ops|pcd|pif|prf|reg|sc[frt]|sh[bsm]|swf|
+  vb[esx]?|vxd|ws[cfh]))(\?=)?"?\s*(;|$)/x
+  REJECT Attachment name "$2" may not end with ".$4"
+
+{% if postfix_header_checks is defined %}
+{% for header in postfix_header_checks %}
+{{ "%-50s %s" | format(header.header, header.action) }}
+{% endfor %}
+{% endif %}