Plesk VPS SPAM

[lexam]

Hello,

I really hope someone can help sort this out. I have a Plesk VPS, which receives tons of SPAM every day. I have already setup the blackhole list filter and Spamassassin. I use the sbl.spamhaus.org list. I must also state that the server acts as a relay SMTP server for the domains that are hosted on it, requiring authentication. The problem is that there is too much SPAM getting through (most of it is marked by Spamassassin, but that's no help actually, as I don't want to configure Spamassassin to delete spam at the server, to avoid losing legitimate mail).

Does anyone have any tested suggestions? Any help is appreciated.

Thank you in advance,
Lefteris

 

[sbillis]

Hi,

I'm not sure what you want to achieve but here goes:

If you want to reduce the amount of spam in general arriving to the box,

1) Implement SPF record checking - you can choose if you block mail without SPF records or if you accept them - have a good read of the help as this explains this feature fairly well. Be warned that you can block legitimate email when using this in some configurations.

2) Use additional spam black lists such as spamcop.org, use reputable ones that are updated frequently.

3) Use a third party spam checking service. You'll need to have an account with them and then change the MX records of each domain to use their mail scanners for inbound mail. Outbound mail from the domains will be unaffected.

4) Enable and use Mail Submission port 587 and disable poprelay locking. This will help if you have clients using your server behind a shared IP address as you run the risk of other people behind the same IP using the server to relay mail through. This is a small risk though.

This will reduce the spam that you receive but be warned, I have servers configured to reject 80% of connections as they come from dynamically allocated IP addresses, of the remaing 20% (1.5Million mail messages) 10% (150K) are delivered to my customers. I don't use third party email scanners BUT I would recommend them to you if you have the budget.

HTH

Simon

 

[wsani]

The Plesk spam mechanism is useless. Try qmail-scanner or try this service: http://www.easyantispam.com/ well worth it...

 

[lexam]

Hello and thank you for your valuable answers.

I followed this excellent IMHO guide (http://www.blueoryx.info/linux_administration/spamdyke) and setup spamdyke, as suggested. I'll have to wait and see what's going down...

By the way, could someone explain what relaylock is? It's not SMTP authentication as far as I can tell. I don't have POP3 lock on. So what is it? Should I stop it and how?

Thanx again