Allow Specific Inbound Mail Only from IP Address

[switt]

Here's my setup:
1) I receive email from three separate IP addresses (a spam cluster before my network)
2) At my firewall, I forward SMTP traffic to my Proxmox
3) Proxmox relays mail to my email server


Here's what I want to do:
1) Limit email I accept to only those 3 IP addresses at the spam cluster
2) Forward mail from those addresses to Proxmox like normal
3) I hope this limits incoming mail to only legitimate email

I can't figure out how to do this so is it possible?

Thanks,
Shawn

 

[tom]

Here's my setup:
1) I receive email from three separate IP addresses (a spam cluster before my network)

configure your firewall to accept smtp only form the three IP´s

2) At my firewall, I forward SMTP traffic to my Proxmox

yes. but keep in mind, that as Proxmox do not receive emails directly, a lot of filtering methods are not possible:
- SPF and greylisting, RBL checks, etc.

All this can only be done if Proxmox receives mail from the internet directly.

3) Proxmox relays mail to my email server

yes.

Here's what I want to do:
1) Limit email I accept to only those 3 IP addresses at the spam cluster
2) Forward mail from those addresses to Proxmox like normal
3) I hope this limits incoming mail to only legitimate email

I can't figure out how to do this so is it possible?

Thanks,
Shawn