Now spam sender is more intelligent and they use IP with PTR and most of the cases their IP not been listed in RBLs like the header.We don’t want to let them do business with spam by taking cloud based solution like zero spam/comodo anti spam.Rather we are trying to find a open source solution that works well against spam.

On Oct 10, 2015, at 7:11 PM, Suresh Ramasubramanian <ops.lists@gmail.com> wrote:

ip block lists are a first and still quite useful line of defense. Spam assassin is a series of score based content filters that supplement Spamhaus and such. SURBL is a URL block list.

Beyond a point however filtering has grown enormously complex (and add issues such as dmarc and other authentication) so your constituents might be better off outsourcing their mail hosting to one of several large players in this field (none that are local to Asia / saarc though)

--srs

On 10-Oct-2015, at 6:34 PM, Suman Kumar Saha <suman@bdcert.org> wrote:

RBL and even PTR record check doesn’t work well.Now spammer also use clean IP and with PTR.Mailscanner/amavis with clamav can’t protect spammers very well.

Thanks
Suman

On Oct 10, 2015, at 6:59 PM, Suresh Ramasubramanian <ops.lists@gmail.com> wrote:

Spamassassin together with free and/or cheap depending on usage pattern block lists such as Spamhaus and SURBL

Mailscanner plus amavis does a sort of OK job on antivirus but that's a different ball game

--srs

On 10-Oct-2015, at 6:14 PM, Suman Kumar Saha <suman@bdcert.org> wrote:

Dear ALL,
In our community mostly using mailscanner or amavis with postfix/exim as anti spam email gateway.But its perfection is not satisfactory now-a-days.Can you share which open source anti spam application works well.

Thanks
Suman
bdCERT