Check to see if you are email blacklisted

Do your clients and colleagues constantly say your email went into their spam filter? So much that you’re worried your domain might be blacklisted? There’s a quick, easy way to check. Go to http://www.completewhois.com/rbl_search.htm and enter your mail server address. For example, mine is 207.174.139.198 (you can get this from your ISP if you’re unsure). After you press GO, the tool will query ALL the 25 major RBLs (real time blacklists).
Once you confirm you aren’t on any of them, you will feel much better. Better yet, you’ll know it’s actually the receivers of your email who aren’t training their spam-blocking software correctly, and you can ask them to add you to their “safe senders” list.

via Laura Stack, via Speakernetnews