SpamHero is an excellent solution for customers at dotCanada.com that want premium spam filtering.  There is, however, one thing to watch out for when using dotCanada.com.  Normally, the MX records we ask you to set up look something like this:

10 example-com.p10.spamhero.com.
20 example-com.p20.spamhero.net.
30 example-com.p30.spamhero.net.
40 example-com.p40.spamhero.net.

But, with dotCanada.com, if you do not leave the original MX records in place, then dotCanada.com will shut down mail services.  To avoid this problem, you must also leave your original MX records in place, but change the priority to 50.  On this priority 50 record, you need to make sure you check the box that says:

"Check this box if this server host your email accounts. Unchecking this box will disable mail reception on this server."

Here is a screen shot of that check box that a user sent:

Note that you should NOT check this box on the MX records that you set up for SpamHero.