E-Mail notifications occurring on success despite configuration in job

Hello --

We are running SQL Server 2008R2 and have several scheduled jobs as part of an overall Maintenance Plan. One of the jobs is the Transaction Log backup. The job in question is configured to send e-mail notifications on failure. During a recent configuration of the server the public profile for the e-mail account for all jobs was set to default, and shortly thereafter, the notifications of successful transaction log backups began to appear.

While this is not a major issue, several administrators have requested that only failure notifications for transaction log backups be sent. I checked the configuration of the job, and it is configured to do just that.

The T-SQL code for the Transaction Log Backups are listed below:

BACKUP
 LOG [RayStationClinicDB_25189] TO  DISK = 
N'T:\BACKUP_25\RayStationClinicDB_25189_backup_2014_02_18_130805_7401648.trn'
 WITH  RETAINDAYS = 2, NOFORMAT, NOINIT,  NAME = 
N'RayStationClinicDB_25189_backup_2014_02_18_130805_7391647', SKIP, 
REWIND, NOUNLOAD,  STATS = 10GOBACKUP LOG 
[RayStationMachineDB_25189] TO  DISK = 
N'T:\BACKUP_25\RayStationMachineDB_25189_backup_2014_02_18_130805_7551663.trn'
 WITH  RETAINDAYS = 2, NOFORMAT, NOINIT,  NAME = 
N'RayStationMachineDB_25189_backup_2014_02_18_130805_7551663', SKIP, 
REWIND, NOUNLOAD,  STATS = 10GOBACKUP LOG 
[RayStationPatientDB_25189] TO  DISK = 
N'T:\BACKUP_25\RayStationPatientDB_25189_backup_2014_02_18_130805_7621670.trn'
 WITH  RETAINDAYS = 2, NOFORMAT, NOINIT,  NAME = 
N'RayStationPatientDB_25189_backup_2014_02_18_130805_7621670', SKIP, 
REWIND, NOUNLOAD,  STATS = 10

The command line for the job itself is the following:

/SQL"Maintenance Plans\RayStation 25 Backups" /SERVER "MGHROSTORAGE2\RAYCLINICAL"  /CHECKPOINTING OFF /SET "\Package\Subplan_4.Disable";false /REPORTING E

Why would success notifications be sent out, and how can the notifications be reconfigured so that only backup failures for the transaction logs get sent by e-mail?

Thanks.