How to prevent IP from Spam List ?

[sriniv...@gmail.com]

Hi to all,

This is one of the incident that happened at my client site.

>> My Client has a Bandwidth Manager, a Firewall and a published Mail Server.
>> His Bandwidth Manager's IP was Listed on the SPAM List and he couldn't send any outgoing mails to his associates.
>> Luckily, Got the Mail server protected with the firewall.
>> Does the Mail Server generates SPAM automatically?
>> He has more than 300 users in the company.
>> He had multiple ISP 's through the Bandwith manager and both the the IPs were being listed on the SPAM List.
>> Got rid of the Problem for the time being. By changing the IP addresses.
>> I 'm worried whether the IP's could once again be Listed on SPAM's.Is there a permanent fix ?

Hope to hear some possible solutions from u all.