Most emails from this user use @aol.com but one has @aim.com.
The only other significant differences I see are that the aol.com one has this header:
X-Mailer: iPhone Mail (20A362)
while the aim.com one has:
X-Mailer: WebService/1.1.21896 aolappiosmobile
This user is not very computer savvy, if he’s doing something to generate the aim.com domain I doubt he knows what it is.
I just don’t see any easy way to force an email address with aim.com into his profile.