I would like to set a regex that will whitelist an allowed domain for all email notifications.
The reason i would like to do this is so that i dont have to worry about email reports being sent out of the organization and hopefully avoid further questions from any future audit of the implementation of Splunk.
If this was something that could be set in the email settings manager that would be perfect or if there is a way to add that validation/whitelist in a conf file for now that would be great as well.
normally i would tackle this with the MTA but i dont own the OS on the servers (managed by another group) and have limited access to change OS base settings.
Any ideas where I could try this whitelist idea to prevent possible data leaks via emailed reports?
I'm not sure this is something that is configurable into out-of-the-box Splunk. You could always file an enhancement request.
One potential alternative might be to hack upon the sendmail.py script in $SPLUNK_HOME/etc/apps/search/bin. Much (all?) of the Splunk email sending functionality would seem to be implemented here. If you're reasonably good with Python, you'd be able to implement this type of change there. Obviously, this wouldn't necessarily be supported by Splunk support - you'd be on your own in terms of defect resolution in this area.