> > I have heavy issues with HOTMAIL since they reject ANY legitim messages > > as SPAM without any reason. All of my 50 Servers are worldwide and in > > different subnets. It is nearly impossible that all 50 Servers have > > spamed HOTMAIL, since my servers accept only authenticated SMTP from > > clients. > > Not "nearly impossible." I work daily with people who run servers > exactly like that, yet spam of all sorts is spewing from their mail > queues. Most of the ones I see are SMTP accounts with weak passwords. > The spammers authenticate as the users and bam, the server is a spam source.
With Exim this can be substantially limited with a ratelimit. http://www.exim.org/exim-html-current/doc/html/spec_html/ch40.html#SECTratelimiting I use something like this. warn ratelimit = 200 / 1h / per_rcpt / strict delay = 10s log_message = Sender $sender_address rate $sender_rate / $sender_rate_period excedes limit delayed 10 seconds It does not work as well when using webmail since messages all appear to come from 127.0.0.1. I did find a plugin for Squirrelmail that limits max recipients and messages sent per day and per account which works well though. Matt > With Hotmail, make sure that you have a reverse DNS record for your > server's sending IP, that the A record for that name resolves to the > same IP, and that your SMTP banner greeting lists the same name. Also, > if you use SPF records, do not use the PTR option - they reject mail > from domains that contain that option.
