Recommendations antispam Pfsense for internal server mail
Hello, I'm looking for an antispam first line to install on the firewall, I want something simple to cut the typical ip's published blacklisted URL, so had thought the package "spamd" apparently has everything I want and so I've had no malfunctions, but … my external mail clients can not send via SMTP, as they have configured SMTP authentication logic and it seems that pfsense installed on the smtpd fails to authenticate and therefore fails sending from external customers. Perhaps no solution to this problem and I have to find another solution antispam, if anyone knows how to fix it please tell me, but .... What do you recommend me install package to filter spam before delivering the mail server and remove and processing load?
My mail server has 10 domains and 200 accounts, is a Quadcore with 3 Gb of Ram and SATA disk, usually receives 10 to 20 emails per minute during working hours, but lately I have 400 points Post the minute me down services temporarily, so I started to remove server load, how can be the antispam. Perhaps there is a solution to limit access to internal SMTP going over 400 such??
WAN -> Pfsense -> 192.168.x.x (mail server)
Mail clients are external, and send and receive through the WAN.
Recommendations antispam Pfsense???
I recommend postfix forwarder for this job.
It does an excellent job of stopping spam bots without any external blocklists but you can add those.