Why are the reports not sending email of more than ~70 events in Suse Linux enterprise?

[hugohctint]

Reports and sendemail not sending an email of more than about 70 events - The maximum number of events varies depending of how much data per event. What I see is that sendemail.py is failing.

Sendemail in the search line is doing the same, and the error is: External search command 'sendemail' returned error code 1.

I tried to add an increase several parameters in the .conf files like indicated on the groups but it did not make a difference
https://answers.splunk.com/answers/542862/how-to-overcome-csv-max-results-to-email.html

Here is the splunkd.log filtered by the scheduler and sendemail events examples:

Scheduler:

04-18-2018 15:00:00.780 -0300 ERROR ScriptRunner - stderr from '/opt/splunk/bin/python /opt/splunk/etc/apps/search/bin/sendemail.py "results_link=https://quebec:8000/app/search/@go?sid=scheduler__admin__search__RMD5305669048a8da3b1_at_1524074400_13" "ssname=R4_TEST" "graceful=True" "trigger_time=1524074400" results_file="/opt/splunk/var/run/splunk/dispatch/scheduler__admin__search__RMD5305669048a8da3b1_at_1524074400_13/results.csv.gz"':      for line in csvr:
04-18-2018 15:00:00.780 -0300 ERROR ScriptRunner - stderr from '/opt/splunk/bin/python /opt/splunk/etc/apps/search/bin/sendemail.py "results_link=https://quebec:8000/app/search/@go?sid=scheduler__admin__search__RMD5305669048a8da3b1_at_1524074400_13" "ssname=R4_TEST" "graceful=True" "trigger_time=1524074400" results_file="/opt/splunk/var/run/splunk/dispatch/scheduler__admin__search__RMD5305669048a8da3b1_at_1524074400_13/results.csv.gz"':  _csv.Error: line contains NULL byte

Sendemail

04-12-2018 12:00:05.484 -0300 ERROR script - sid:scheduler__admin__search__RMD5bf6f3132e2acfda9_at_1523545200_31 External search command 'sendemail' returned error code 1.

Appreciate your help, thanks