Anyone notice a sudden increase in Spam?

[Boe Dillard]

I support about 10 tenants with 365 hosted email.  5 of them reported to me in the past week that they are getting inundated with spam going to their inbox (not spam).   I haven't changed anything about their hosted environment but I'm wondering if there was a 365 outlook client update that might have changed things?   I called MS and they said nothing has changed.  I've never had so many end uers from so many different tenants all complain about an increase in spam.

Again, I've changed nothing about their hosted configuration.

[#2]

@Boe Dillard 

We cannot foresee the actual and trend of Spam from outside, btw, your Email gateway also hosted in Office 365?

[#3]

YES!

[#4]

Yes all the different companies with their own tenant / company / domain are on 365 hosted.

[#5]

Yes, I have 2 tenants with O365 and in the last 2 months we have noticed a marked increase in SPAM