sending email to groups from non-user (to validate the email address!)

sending email to groups from non-user (to validate the email address!)

Hi,

I'm trying to setup an email system to send an email to one of our groups using the group id email. But it is coming from an email other than a group member and failing.

So I then tried to set it up to be forwarded from my account (a custom domain gmail account) but gmail sends a verification too, from another email address - so that doesn't arrive either.

Is there any way at all to send emails to a group from a non-member address? If not, how do I validate an email like this?

Thanks
John