albatroz
You can install the newer spamassassin rpms from
http://spamassassin.apache.org, and also any required dependencies, but not sure if they will work correctly with the contrib (panel).
If you are really keen, you could remove the panel and just enable spamassassin manually without using a server manager panel to control it.
> I can´t yet upgrade upgrade to SME 6.01
Why not ?
You will have a much easier time if you upgrade to sme 6.0 or 6.0.1 as there are well developed and supported contribs available.
In 6.x you also have the RBL functionality which in itself is worth doing the upgrade for. RBL really has a big impact on spam.
Your server should upgrade OK from 5.6 to 6.0 as this is a supported upgrade path, just remove any incompatible contribs first. All the contribs you are likely to need have been released for 6.0.x anyway.