Spam-filtering is done by Akismet, a web-service that tests the comment against its large set of rules and gives it a thumbs up or thumbs down. If Akismet flags a comment as spam, all subsequent comments made from the same IP address are automatically flagged as spam. Comments flagged as spam go into a queue that can be checked by the website administrator for false positives (legitimate comments incorrectly flagged as spam). False positives released from the queue by the website administrator are sent forward in the publishing process. Additionally, a copy of the false positive is sent to Akismet to help it learn not to flag similar comments as spam going forward.

Note also that Akismet is a global service that examines millions of comments every day from many different sources. For that reason, you’re more likely to have a comment incorrectly flagged as spam when you post from publicly-accessible IP addresses (libraries, coffee shops, etc.). Many comments are made from those IP addresses, which increases the likelihood that someone using one of those IP address before you has made a comment which Akismet has flagged as spam, thus flagging all subsequent comments from that IP address – including yours – as spam.

WordPress’s whitelisting feature is based on user-submitted email addresses. Whenever WordPress sees a comment from a new email address, the comment is held in a queue for review by the website administrator. If the website administrator releases the comment from the queue, WordPress records the email address. Future comments from the email address bypass the queue and are posted on the website immediately.

Note that the Akismet spam-flagging process is executed before the WordPress whitelisting process. Even if the website administrator has already approved your email address and placed it in the whitelist, your comment can be flagged as spam by Akismet.

[The above is based on my admittedly limited understanding of Akismet and WordPress functionality. Caveat emptor.]

Pretty much all blogs have no comment delete option. If you want something deleted, you have to write to the webmaster and ask nicely.

Anyway just a thought.

We haven’t re-set anything. To be honest, I’m not sure what that whitelist is keyed to — I assumed IP address, but maybe that’s wrong.

In any case, that comment has been set free and is visible here.