Forward email from private network to internet email address
 

We have a small private network and have added some devices that send notifications by email (not SMS). What I'd like to be able to do is have the emails sent by these devices forwarded to my public email address. There is currently no other email traffic on this network and the only emails sent are from these devides

There is a server (dual NIC) on the network that is connected to both our private network and the internet that could do the deed. It is running Debian 11.

Can Sendmail do this or is there a better option?

Assuming the devices can't directly access the internet then sure, Sendmail will work. Ensure Sendmail is listening on the private interface and configure the devices to use that as the outbound SMTP server.

Usually in most corporate situations you would have a demilitarized zone which is usually where you would put servers like web servers,Email servers and ftp servers. If I'm in the correct belief by reading your post the machine that may conceivable be used as an Email server sounds to me like it could an adequate host to be used as an email server.