For some company,they do not have much knowledge about the mail record setting,most of often,they do not set any spf,dkim record,what they have is only A,MX record.

For example,there is a domain,like  aaaa.com,they only have below records:

@   A   11.11.11.11

mail  A   22.22.22.22

@  MX  mail.aaaa.com

If some spammer use the above domain and forged to send mails to xeams,it is easily to INBOX,if the IP is clean(Not in any RBLs). So i think a new filter is needed for such spams. 

If spf none and not from A and MX record's IP(11.11.11.11 and 22.22.22.22),asign socre to it.

Consider this done for the next update. Let us know if you want to test this before a release is made publicly available.

Good to see most of my suggestions are accepted here. extract styles,null sender at NDR,MissingSPF.

By check for update from control panel,seems latest version not ready???  Says: No new version