If it were her own, she would claim the 5th again, my guess. of course, if it were IRS property, she has no such defense available. Hummm, who also has a Blackberry (probably loves the name)??? The IRS probably has a contract with them.
BTW, my wife’s employer insists on using the Blackberry albeit most employees have migrated to I phones long ago and ignore the demand.
Oh, they'd get a warrant for that in the blink of an eye. It's prima facia evidence of wrongdoing if she's using a personal emial account to conduct government business.
In this case, however, the emails show that they come from her work account. So whether it's her device or the government's (and knowing the way the government works, it's almost certainly the latter), the email server is what would be looked at, not the device itself.