After about a week-and-a-half, Google finished unclogging a backlog of legitimate messages its Postini spam filter trapped by mistake at the end of February.
Google finally cleaned up the queue of undelivered email early Sunday, resolving a problem it first acknowledged on Feb. 26. The company started sending out the affected messages the next morning.
This means that the last batch of erroneously quarantined email reached its destination almost 11 days after being sent, about three or four times longer than it usually takes the U.S. Postal Service to deliver First Class mail.
"The problem with Postini Services should be resolved. We apologize for the inconvenience and thank you for your patience and continued support," reads a note posted by Google on its Apps Status site shortly after 1 a.m. U.S. Eastern Time Sunday. "All messages that were Quarantined as a result of this issue have now been redelivered."
Asked for comment, a Google spokesman said via email that the redelivery of the messages "was staged over a number of days to ensure no impact to normal mail delivery and to not overwhelm customers' email servers with sudden high volumes of incoming messages."
He didn't immediately explain the scope and cause of the problem.
In a previous update posted Feb. 27, Google said that it would take "several hours" for all messages to be reprocessed.
Postini spam filters and antivirus services are used to secure Gmail as part of the Google Apps suite, and they can also be used with third-party email providers and enterprise servers.
Google announced in mid-2012 that it would phase out the Postini email security cloud services, and gradually integrate the technology natively into Google Apps and into the optional Apps Vault email archiving, discovery and compliance service.
The process is still ongoing, according to the Postini Transition Resource Center page and accompanying timeline.
Juan Carlos Perez covers enterprise communication/collaboration suites, operating systems, browsers and general technology breaking news for The IDG News Service. Follow Juan on Twitter at @JuanCPerezIDG.