Why did Gmail lock me down in sector 4?

March 24, 2005 3:51 AM

Yesterday morning, when I tried to collect my Gmail messages, Thunderbird told me the server had reponded "Lockdown in Sector 4!". I couldn't get into Gmail (POP3 or webmail interface) all yesterday and all today; it's come good tonight. Has this happened to anybody else? If so, have you ever found out why?

Trying to log in to gmail.google.com took me to a page that told me my account had been locked down for "up to 24 hours" due to "unusual usage", including a reporting address to use if I didn't think I'd done anything to violate the TOS. AFAIK I hadn't, so I fired off several queries (took me a while to remember that I'd set the reply-to: on all my mail accounts to my Gmail address). So far, all that's got me is unhelpful autoresponses reiterating the web page text (irritatingly signed "Sincerely, the Gmail team"). Short of prostrating myself three times daily in the direction of Mountain View I have no clue what, if anything, I should do or stop doing to avoid this happening again.

I have just about got over the annoyance of being locked out of my main mailbox for two days, and I'm now mostly curious. Is this just the Gmail team subjecting randomly chosen guinea pigs to tests of a new security feature, or is there something I'm doing "wrong"?

My normal method of getting to Gmail is via Thunderbird and the AVG 7.0 Free e-mail scanner proxy, with Thunderbird's default 10-minute POP3 polling cycle. I don't send mail through their smtp server - I use my ISP's. Right before this happened, a friend had just sent me a draft of her PhD thesis to review (a 14MB attachment); this is the biggest mail I've ever been sent, and I have not yet downloaded it.

Is there anybody here with inside knowledge?

posted by flabdablet to computers & internet (5 comments total)

Not inside knowledge, but maybe somebody was trying to brute-force/guess your password? Plenty of webmail clients lock down after a certain number of errors...
posted by michaelkuznet at 5:32 AM on March 24, 2005

Right before this happened, a friend had just sent me a draft of her PhD thesis to review (a 14MB attachment)

You're over the attachment size:

With Gmail, you can send and receive messages up to 10 megabytes (MB) in size. However, the precise amount allowable will depend on the attachment.

posted by jbrjake at 7:14 AM on March 24, 2005

Did you try Google? This is mentioned on several blogs, e.g. here: Lockdown in Sector 4.

When presented with an unintelligble error message, always type it into Google first.
posted by mcguirk at 8:39 AM on March 24, 2005

Michaelkuznet: Thanks for your guess. I'd already guessed that guess, along with several others: maybe Tash's thesis is too long; maybe my POP3 polling cycle (Thunderbird's default 10 minutes) is too quick; maybe they don't like me using some other smtp server instead of theirs; maybe they're just testing their new lockdown feature and I was a randomly selected guinea pig.

Jbrjake: I've pretty much eliminated your guess, on several grounds: (1) if Gmail responds to attempts to download a large attachment by locking down the downloader's account, that makes possible an incredibly easy DOS attack on Google's customers - so they won't do that; (2) I just attempted to download that attachment again; the connection broke at about 30% completion, but my account has not been locked down again.

McGuirk: of course I did, and all it ever got me was the same uselessly vague non-explanation you've linked me to. No soup for you!
posted by flabdablet at 3:00 PM on March 25, 2005

OK, you have a point-- I didn't read the question very well.

In what you've written, you don't seem to distinguish between receiving the attachment and downloading it. It could be that receiving the attachment was what caused the lockdown. You could test this by sending another 14MB attachment to the account. Yes, that mechanism would create a potential DOS attack, but this is still a beta; who knows how refined this security mechanism is.

I suppose I could try that on my own gmail account, but I'm not particularly interested in being locked out for 24 hours if that is the explanation.
posted by mcguirk at 9:53 PM on March 28, 2005