We have a bought in, line of business, application that has a primitive email client built into it. It sends out PDFs it creates on the fly to suppliers, landlords and tenants. There is little to no possibility of it being changed.
Problem 1 - missing Message ID
It creates very simple message headers - and in particular does not create a Message ID header.
https://wiki.apache.org/spamassassin/Rules/MISSING_MID complains and assigns a spam score of 1.6 This is not good for us.
Problem 2 - no S/MIME support
Exactly that - emails are created and despatched with no possibility of encryption
Solutions for prob 1?
A. Send those emails to my own application that corrects them as needed then forwards them using SME Server qmail?
Or
B. I have had a look at the qmail docs and it seems that there is a utility qmail-qfilter which allows messages to be altered before they are passed to qmail-queue. I presume it would be fairly straightforward to add a message-ID header if it were missing.
Solutions for prob 2?
As above - but now, if we find that we have a key/cert or whatever it is called for the recipient we also S/MIME encrypt the body.
Has anyone any experience of doing either of these things? using qfilter? Is it already in SME Server?
Any thoughts, pointers or ideas very welcome.
Thanks