sendmail configure question

[mdjbhouse]

I'll admit to not being very wise in the ways of administering sendmail.
My question is this.
We have an app that will send out a bunch of emails to customers via our external email gateway configured as DSsmtpxxx. We have already determined they are in error.
So the question posed to me is can I stop those emails from getting sent, ie. just let them get stored locally and then delete them?

I know in the past I've had issues with sendmail being misconfigured and mail pilling up (check via mailq) so I kind of want to do that again. Just not sure how exactly.
If I shutdown sendmail will that work, mail spools to /var/spool/mqueue and then I can just delete it or how do I accomplish this? If I remove my DSsmtp: entry mail doesn't go to my external gateway server so I can stop it that way but again I'm not really sure...

[mdjbhouse]

I think if I just pick in an erroneous smart host entry my mail will fail and I think the messages will just pile up as messages that couldn't be delivered and then I can delete them out of the senders mail file?