I have a Sun Solaris system running Sendmail Pro. I have setup the relay-domains file so that it will only relay mail for our corporate domain to avoid spammers.
The problem I have is how to allow my users to access the SMTP gateway while dialing in through their ISP’s. The Sendmail system is located at our ISP and we are using a VPN to allow remote users to access our local systems. The VPN doesn’t help my problem, because even if users come in through our VPN they still show up to our Sendmail system as coming from their ISP. The VPN software is setup so that any internet access goes out through the users ISP and doesn’t go back through the VPN and out the corporate T1.
We have tried setting up users so that they use their ISP’s SMTP gateway while traveling, but some ISP’s have blocked any mail that doesn’t originate from one of their e-mail accounts.
Has anyone run into this before? Should I setup a Sendmail gateway inside our corporate net, so that users can access it via the VPN? Is there any way