We are currently using MxGuardDog for spam filtering. It works by pointing our MX records at their mail servers.

The service seems pretty good, it keeps out the obvious spam, but I would still say it let's through mail that to me is spam, but I accept that on the surface those emails may not flag any of the universally recognised indicators for spam. If an email comes through that I believe is spam, I can login to the Web Console and blacklist the email/domain. However, 99% of the time I don't because it's inconvenient - or, should i say, it's far less convenient than a button in Outlook that allows me to report the email/domain as spam.

So, what we're looking for is a similar service i.e. cloud spam filtering that has an Outlook plugin so that Administrators/Users can report spam.

We are only a small company, 10 users, so cost is of course an issue for us.

Many thanks dotdev