Sending a PDF attachment - 554 Malicious Message

I’ve emailed to myself a SIGNED contract from my office using a SCAN-TO-EMAIL Fax/Printer as a .PDF file … saved and renamed the file into my notebook, prepared a formal email to the other parties in MS Outlook 2010, attached the renamed file to it and try to send it to them.

The email doesn’t go out… I keep receiving this message:

The following recipient(s) cannot be reached:

  Angela (astixxxx@xxxxxxxxx.ca) on 5/05/12 1:50 AM    <---  (email address changed for privacy)
        554 Suspicious message

It took me a long time, but by removing “scan attachment when attaching” in OUTLOOK ONLY, I finally was able to send it out.

Now, using the same MS Outlook, I was ALWAYS able to send any kind of files attached, including .pdf files… why is it happening now with those .pdf files that I’m sending to myself from a Multi-Funtion printer?

Any ideas?

Cheers,

Broano