IP's are a critical part of 3rd party bulk email marketing. The IP you send from can dramatically increase or hurt your deliverability. A fast way to check your IP is by going here . You manually enter in your IP address and the system will run it to check if it is blacklisted. If the IP is blacklisted on barracuda, there is no real worry. Most IP's are blacklisted on barracuda. However, if you see that you are blacklisted on Sorbs and Spamhaus, you need to get a new IP. Being blacklisted by these two sources will drastically hurt your deliverability.
So how can I use bulk email software and not get blacklisted?
Google.com states the following about why you can get blacklisted.
"Some domains might use a Realtime Blacklist service (RBL) to identify and block email from suspected spammers. If enough of those domains' users mark email received from a particular IP address as spam, the RBL can blacklist that address, blocking all email from it. If your email is being bounced, it's possible that an RBL service has blacklisted your domain's IP address."
To stay away from becoming blacklisted, clean the lists you send bulk email to and make sure that you are including an unsubscribe link.