The problems started on Sunday morning when many users could not access their Gmail accounts online. Google soon admitted that the details had been lost on its main systems, and that it was restoring these missing accounts from tape.
As reported by Computer Weekly, Google blamed the problem on a software upgrade causing account deletions, but has since claimed that the outage only affected 40,000 users.
In a Twitter message posted late last night, Google apologised for the problems, saying: "An apology on the recent Gmail issues," adding that "Gmail should be back soon for everyone."
Despite this assertion, as of 15.00 UK time on Tuesday 1st March, many users still said they were unable to access their mailboxes. It also appears that still more users who could log into their accounts, found many of their archived messages had disappeared.
Google is painting a rosy picture on the outage, claiming that only a very small number of accounts were affected.
"The good news is that email was never lost and we've restored access for many of those affected", said Ben Treynor, vice president of Google's engineering and site reliability, in a Monday evening (US time) blog.
Unconfirmed reports, however, suggest that Gmail has admitted to affected users that messages sent to their mailboxes between 9pm Eastern US (2am UK) on Sunday night and 5pm Eastern US (midnight) yesterday "was likely not delivered."
Google isn't saying, however, what has happened to the messages, nor whether they will be delivered. The messages did not bounce back to the senders, Infosecurity understands.
The online giant says it is restoring the affected mailboxes from take backups, but this process takes time. The company is posting updates to the Apps Status Dashboard.
Reaction to news of the outage has been mixed, with some experts saying that users should use POP3 client software such as Outlook Express or Mozilla Thunderbird to automatically retrieve their email as a backup, even if they prefer to use a Web-based email interface.
Paul Watson, chief commercial officer with Star, an on-demand business service that offers email and telecoms services, said that the deletion of so many Gmail accounts once again highlights the inherent risks associated with international public cloud services.
It also, he said, underscores the need for businesses to opt for email solutions that closely fit their requirements.
"Business grade private cloud services delivered from the UK give all the benefits of the public cloud - such as scalability, removal of capex and simplified management - but with the added reassurance of knowing where your data is stored, where it's backed up and having a guaranteed level of security, service and customer support built in around this", he said.
"With Gmail there is little visibility or transparency on where the data is housed and when something goes wrong, there' little recourse available", he added.