I was trying to install Nokia Messaging on my Nokia N900 and could not. Online it says that my phone is already equipped with the latest software. On my phone Nokia Messaging is not in the list of email services, no matter what country I tried and how many times rebooted.

I have a SIM from the Canadian provider (Wind Mobile), so the tricks with SIMs that others described for USA providers won't work.

Please advise.

It depends on your provider ,this service is available for certain providers rather than the others ,as for me i borrowed my friend's sim card ( different provider ) added the service then put back mine....
I have no idea which providers the service is available for in Canada ... that you should google your self .
Hope this was helpful.

Thank you for taking the time to reply. I understand this is an official bug with Nokia?

Annoying though it is, that Nokia Messaging is only available when Nokia devices are used with certain service providers is the intended behaviour, not a bug.

no it is not a bug ,according to the email i was sent by nokia when i created mine they stated that after one month of "trail period" i should contact the provider in order to obtain a permanent activation of the service for a certain fee ... so i think they are making money out of it by charging your provider which is charging you as well.