Hi Jonathan Can you not restrict the SMTP relay to allow only those allowed servers and reject emails from all other sites? or may be allow only specific domains to relay through.
Regards Ahsan On Mon, Feb 1, 2021 at 3:02 PM Jonathan Sélea <jonat...@selea.se> wrote: > Hi everyone, > > We currently have a webhosting-environment with many websites. Those > websites is capable of sending email (obviously) via the local SMTP > function. > But sometimes, some of the websites is compromised and used to send > quite alot of spam from the websites - often using random domains. > > So, one of the "solution" would be to implmement some kind of filter, > that check the SPF of the domains on outgoing emails and check if they > include or contain the IP or network of our environment and if not, the > emails is just discarded. > Ofcourse, we would employ more anti-spam features, but this would be > only one of them and could probably save us from blacklisting in some > cases. > > Thankful for your answers! > > -- > Jonathan Sélea > > PGP Key: 0x8B35B3C894B964DD > Fingerprint: 4AF2 10DE 996B 673C 0FD8 AFA0 8B35 B3C8 94B9 64DD > >
