context: I'm upgrading from an old civicrm 3.4.5 (d6) to 4.7.22 (d7) and have done so apparently successfully..
I see reference that bulk emails are no longer listed in the activities tab by default from 4.4.4, but mine are still there.
i've "solved" this by unticking "Enable CiviMail to create activities on delivery" in CiviMail Component Settings, which makes a nice mailing tab, and then deleting all previous bulk email activities - but i'm confused as to why they are not hidden.. and slightly concerned it's some legacy from my upgrade and other things might be affected too.