Apparently any email containing a URL to this journal (http://11011110.livejournal.com), even as plain text, is being interpreted as "URL Obfuscation" by the AT&T Research email servers, and permanently blocked. I haven't done enough experiments to tell whether they don't like any URLs, or just not mine, but my guess is that it has something to do with the purely-numeric domain name component.
It used to be that everyone used the old style, and you still can:
Moving your username to the dns address was a pay feature, and a pretty neat one, I'd say. But about 5 years ago, someone found a browser flaw where a special custom layout could capture the authentication cookie and impersonate with it. A substantial number of LJ's were hijacked, and an immediate fix was to switch to the dns addressing for everyone, so Brad did that.
Yes, this sounds vaguely familiar. I just checked; I still have posts from 2005 using the old URL syntax. Will try that the next time I want to get a message through.
According to WolframAlpha you are indeed not a number, but two places 9353 km apart.
Cute. I didn't know my first name was a place.