One administrator's contact record is duplicated every time she performs the Activity action "Send email". The recipient's activity record indicates it was "added by" and points to a new contact record with the first, last and email of the administrator (no WP account associated with it). (There are now a very large number of these duplicate records!!)
Note, when she sends bulk emails, that activity is recorded under her correct logged in contact (associated with her WP account).
We thought it might be because there was a "From email addresses" associated with her name/email, but disabling it didn't help. (Can't be deleted without removing linked activity records which is not desirable). And another administrator with a From email does not duplicate.
I tried logging in as her and it still does it, so it is not the sequence of actions just she is performing. When I and other administrators send emails from our admin accounts, there is no duplication.
Has anyone seen anything like this before?