Why am I unable to receive email from LiveJournal? says (in part) --
Check the space available in your email account. Many email service providers place limitations on the amount of email you can store in your mailbox. If you have space available in your mailbox, then it is likely that some or all of your LiveJournal email is being filtered or blocked as spam or junk mail. Check the spam or junk mail filters on your email account. If it is possible for you to adjust or edit them, add livejournal.com to the "allowed senders" list (sometimes called a "whitelist"). It may also help if you add livejournal.com to your address book. If it is not possible for you to adjust or edit your filters, you may need to disable them entirely. Also, certain Internet services provide parental controls which can interfere with proper email delivery.
If you have adjusted or disabled the spam or junk mail filters on your e-mail account, or do not know how to do so, and are still not receiving LiveJournal e-mail, you will need to contact your e-mail service provider for further assistance, and tell them that you are not receiving legitimate e-mails from livejournal.com. Many e-mail providers are not aware of the mail filters they have in place.
It is important to realize that most server-level spam filters (and many client-level ones) filter based on origin or source IP address -- not on domain. This is the way that most blacklists function -- and is probably the way that the service noted in the status posts works --
A popular spam-blocking service has listed us on their block list, most likely because of the volume of email we send. Our system administrators are working with them to get un-listed. In the meantime, you might be unable to receive any email from LiveJournal if your mail provider uses server-side spam blocking.
The existing FAQs which discuss mail, whitelisting, and filtering, should all include the IP address as well as the domain name -- and they should generally replace the domain name with the source hostname or FQDN.
Until this evening, when I got a response from my suggestion, I had no idea that everything LJ was behind a single IP address -- that seems sure to bring madness, speaking as a long-term admin -- but it does make things easier to fix.
... Check the spam or junk mail filters on your email account. If it is possible for you to adjust or edit them, add livejournal.com, mail.livejournal.com and/or 220.127.116.11 to the "allowed senders" list (sometimes called a "whitelist"). ...
I would suggest that this information also be provided in the STATUS postings in future, any time you become aware of a spam filter / blacklist which includes the relevant IP address(es)....