This post is about my personal journey with a cross-forest migration.
When it comes to account migration there is no way to do so without sIDHistory. It would be really hard to have a smooth migration without.
By using this attribute a end-user most likely won’t experience any impact…..unless you start doing a cleanup of this attribute.
In terms of Exchange users might see something like this
But what’s behind those issues and how could you mitigate this? I was part of a migration, where those issues popped up and I’m going to describe how you could determine possible impact for end-users before it happens.