What exactly is it connecting to? Something along the lines of Spam-Assassin?

It's connecting to Spamhaus, and if not available or overloaded, to alternate services. It has also a local database where known spammers are cached for some time.

Why would someone make themselves dependent on an external resource?

If somebody was so badly spammed as some of my servers (hundreds of spammers and tens of thousands of posts), and any service would help me to get rid of them, I would choose it. I have made my research and found that nothing exists which compares to Spam-Assassin, and so I coded the connection to those databases. Also I added some of the features I had already, such as the local spammer database and formal email checking. All together they do a really good job.

What happens to a new post of your service is not available?

New posts are not affected, only new users.

Can you elaborate a bit more, please?

What does it do with the spam, etc. how do I know it is not removing legit posts, etc. we need more detail.

It does not allow to register spam bots and notoriously known spammers from certain IP's.

If a user registers, it's email (and optionally IP) is compared to the local database (our's) first and if a match was found, rejected.

Flow:

• An incoming email address is formally checked and rejected if invalid.
• If no IP match was found, it connects to the world-wide spammer databases in a certain order, and if there is a match, the IP is stored locally and the user email rejected.
• If the email address appears not to exist (MX lookup & initiation of email transmit, quit before sending), the user email is stored to the local database and will be rejected.
• If none of the above applies, the user may register. At this point it is sure the email account is not coming from a known spammer and the address is really valid.

You may test this service by issuing:

http://uspam.pagerobot.com/index.php?email= Questo indirizzo e-mail è protetto dallo spam bot. Abilita Javascript per vederlo. &ip=64.201.124.1

for a known spammer, and anything else for valid or invalid email addresses. If no IP is specified, the IP test against the world-wide databases is not performed.

If the email is invalid, a page with 0 is returned. If the service is manually down, a negative value is shown. If the email is valid, a 1 is shown.

Which EMail addresses are stored?

If the originating user comes from a world-wide banned IP, only the IP is stored, since any email from that IP is used for spamming. If the given email fails to authenticate with the destination mail server, it is stored for a short period.

Thus, USpam stores only globally banned IP's and invalid email addresses. All other information is silently discarded.

Please visit also the USpam Home Page in order to obtain more information.

I am unable to register my own email address.

I uploaded this to my site and I tried to register with my e-mail address and it said Invalid e-mail address I uninstalled and it worked fine was I doing something wrong?

If your server's IP is blacklisted on SORBS, sbl.spamhaus.org, xbl.spamhaus.org or bl.spamcannibal.org, it can not access our service. We have added this protection quite some time ago in order to avoid registration attempts from already compromised systems.

Similarly, if you are trying to register from home (probably a dynamic IP), and this IP has been used for spamming, it finished probably in the Spamhaus XBL list, and thus you are not allowed to register. Also, your PC may be infected by a worm which sends spam to our honey-pot, and thus gets blacklisted.

In addition, if your mail server was down, or your mailbox was filled completely (mailbox quota exceeded), you will not be able to register, because you never would receive the activation email anyway.