If, after installing the PoliteMail for Outlook add-in, it doesn’t load but instead Outlook gives you and error dialog that says “Load Behavior not loaded Certificate of signed and load at startup com add-in is not trusted source list” then you most likely need to run Windows update or Office update.

The PoliteMail COM add-in for Outlook is a signed with an SSL security certificate, which must be trusted by the Windows OS and Office system. If you are running an older Windows system, such as Windows XP, and you are not up-to-date with patches and service packs, then the list of root certificates may not included the newer security cerficiate used by PoliteMail to sign the add-in.

If you run both Windows Update (and include the root certificates update) and Office Update, this should resolve the issue.