[taeric]

If they have given a side channel to impact my calendar, that will cause issues.

Sure, for many folks this will be fine. But it seems an unnecessary denial of service attack vector that needs more engineering to protect than makes sense.

[emodendroket]

I would guess in the many years they've had this they've had to iron out some issues, but allowing you to receive e-mail at all is a denial of service attack vector.

[taeric]

True. But it is only a denial of your email service. Allowing it to leak over to other services is not good.

[emodendroket]

You could think of them as different facets of the same service, like Exchange.