[CentOS] how to monitor,or be notified of email blacklisting ?

[Ned Slider]

Rudi Ahlers wrote:
> Hi,
> 
> Does anyone know how I can monitor our server's for blacklisting? We
> run a large amount of shared hosting & reseller hosting servers and
> from time to time one of the IP's will get blacklisted. I'm looking
> for a way to be notified if any of our IP's get blacklisted. Is this
> possible?
> 


You could manually check your IP address(es) here:

http://www.dnsbl.info/

Alternatively, just read your logs (or write a simple script to parse 
them for you). You'll receive a 5xx rejection and usually a reason/URL 
from the main blacklists whenever you are blocked.

If you're using postfix as your MTA, check out pflogsumm.