James Freer wrote:
  

... while talking to greyhoundhomer.org.uk.:
 >>> >>> RCPT To:<sally@greyhoundhomer.org.uk>
<<< 550-Callback setup failed while verifying <jessejazza@aim.com>
<<< 550-Called:   64.12.138.120
<<< 550-Sent:     initial connection
<<< 550-Response: 554- (RTR:CH)  
<<< 550-554  Connecting IP: 65.98.59.114
  
    

The server handling greyhoundhomer.org.uk is performing some tests 
against your email address. I assume it testing whether or not your 
address is valid (presumably jessejazza@aim.com is your address?) and so 
looked up the mail server which handles your email and connected to it, 
or rather tried to.

That server (belonging to AOL) rejected the connection, and so the 
assumption was made that your address was invalid and your email not 
accepted.

For whatever reason (based on 
http://postmaster.info.aol.com/errors/554rtrch.html confirms) the 
address in question (that of greyhoundhomer.org.uk) has been 
blacklisted, perhaps because spam has been sent from that address in the 
past.

Now the IP address in question (Connecting IP: 65.98.59.114) belongs to 
FortressITX in the US (according to "whois 65.98.59.114" , so I assume 
this is some 3rd party email server, not one belonging to 
greyhoundhomer.org.uk (unless its some cheap US hosting package). 
According to MXToolbox (www.mxtoolbox.com/blacklists.aspx) the IP is not 
listed in any of the 120+ blacklists it checks. Therefore it may be that 
the problem is resolved, unless AOL has its own lists.

To cut a long story short: AOL (and similar free addresses) are not 
reliable for anything these days; they are heavily targetted by spammers 
(both for sending from and to), and the varied, changeable, and largely 
random methods used to stop spam tend to cause at least as many problems 
as they solve. I would not advise anyone use them for anything!

PS: Also: What Ted said!