Recently, due to client requirements we’re doing a series of tests about how to migrate a bunch of attributes to O365. But we found a simple (and silly) problem that stuck us for a couple of hours.
At first glance, we were able to migrate some users from OnPrem to Office 365, but then we started playing with some other AD attributes, one of them, was ProxyAddress.
We were trying to set the following proxyaddress onprem and try to synchronize it in O365: email@example.com. At first glance, everything seems ok, because we were able to see in the ADConnect client that this attribute was exported to O365, but when we tried to examine this attribute in O365, was impossible to sync it.
We did a lot of things, and we run a lot of tests, including full syncs, delta, etc… and finally we discovered that it is not possible to sync a proxyaddress from onprem to o365, which contains *.onmicrosoft.com.
So, sometimes we have to follow KISS procedure and try to no rebuild the wheel…
Hope that helps!