Why such an excessive number of Transaction Logs 2013

We only have 13 users.

We have 110,000 Transaction Logs taking up 100GB IN ONE DAY.

This is insane.

I'm running Exchange 2013 SP1 on 2012 R2 (and yes it is the domain controller).

One email message might generate 50 logs.

We are using a Split Domain and I did disable IPV6 through registry before installing Exchange 2013 SP1.

Other than this everything is running smooth.

I know the Logs will purge after full backup.

But this seems way too excessive.