UPDATED 5th JULY 2004 - A mass email was sent to Hotmail users in the UK over the past weekend, properly announcing the changes as detailed in our update below, promising to outline the timetable within a fortnight. When we know Microsoft's roadmap, we'll let you know when your mailboxes get much, much larger.

UPDATED 28th JUNE 2004 - Maybe Microsoft has confused the calendar and business idea of Summer. After the triumphant announcement of these larger mailboxes on Thursday, Hotmail users in the UK at least, woke up to the news on the Today page of their email accounts that only antivirus filtering of incoming mail is to be added within the next month.

The would-be Yahoo-killing 250Mb mailboxes, with matching 10Mb attachments, will now not arrive until Autumn. The link in the Hotmail Today page sends you back to Thursday's original announcement which still implies all upgrades will be phased in over the summer. They must mean the British cinemagoing summer then, which runs up to September 30th of every year. Either way, Yahoo and Gmail seem to have the summer all to themselves and being free, of course many users will have one account each used to varying degrees and for varying purposes.

We'd like to thank whoever corrected our original headline, but have to point out that until the Autumn, Yahoo's free mailboxes remain 50 times bigger than those of Hotmail.

ORIGINAL STORY - We were waiting for Microsoft's response to Yahoo's expansion from 4Mb to 100Mb free mailboxes from a week ago.

Over the last 24 hours via the MSN website and official email announcement Microsoft told its Hotmail users that all 2Mb mailboxes were to be increased to 250Mb instead, one and a half times bigger than Yahoo. Yahoo's 10Mb attachment maximum has also been matched by Microsoft. However the 90-day expiry on inactive accounts remains and can only be removed by upgrading though.

Anyone who had already paid for MSN Extra storage to go to 10Mb will have had the same boost to 2GB as Yahoo users, however to continue using the newly renamed MSN Hotmail Plus will cost £3 more than Yahoo at £14.99 annually. However the extra money buys the ability to send attachments totalling 20Mb, useful if you are emailing your gap-year foreign photos using Hotmail.

Antivirus protection may now be applied to outgoing mail as well with Hotmail, giving it the air of an entirely online Outlook XP but normally this would only really prove useful if you were sending an attachment with your message. If your Hotmail is linked in with a POP3 mailbox however, that's one area where sending mail back out again may benefit the user when it's virus checked.

Early July is the quoted launch date for these changes, which could be as soon as next week or in the next fortnight. Given that Yahoo jumped first and the doubled attachments cost an extra £3 annually, user inertia may stop Yahoo premium customers from switching at least for this first year As ever the real winners are the holders of free accounts, who will almost certainly stick with a service offering 1.5 times more space than Yahoo.

It's horses for courses seeing as Hotmail's insatiable worldwide demand can sometimes crash the site (something we know about at pocket-lint.co.uk all too well). Ironically it's Yahoo who has suffered more Denial-of-service attacks than Hotmail; hackers seem to prefer the operating systems instead. It's all very exciting stuff in the online email battle; but will it be enough to see off Gmail coupled with ongoing privacy concerns? We'll report as Gmail launches to see whether Microsoft, or perhaps more importantly Yahoo, can fend off the Google challenger.