For the third time in five months, potentially millions of Gmail users were unable to access their accounts in some parts of the world due to an unexplained outage. The e-mail blackout occurred about 2 p.m. EST Monday.

According to some published reports the outage also affected other Google services such as Google Drive, the new cloud-based storage system, Google Docs and Google Play, the mobile Relevant Products/Services apps and content store.

Google did not acknowledge the issue on its own official blog but added its symbol for "service disruption" with Monday's date on the dashboard for Google Apps under Google Mail, Google Drive and Admin control panel/ABI.

Sorry About That

In a later statement published by some media, Google said "we are currently experiencing an issue with some Google services. For anyone who is affected we apologize for any inconvenience you may be experiencing."

Using a New York-based account on Monday we experienced no issues with Gmail, but sporadic reports suggested an authentication issue, particularly when used with Google's Chrome browser.

According to October figures from research firm comScore, Gmail is the world's top e-mail provider, with 287,913,000 unique visitors that month, compared with 286,238,000 for Microsoft's once dominant Hotmail and 281,722,000 for Yahoo! Mail. The figures were for worldwide users.

"Google's service has become so broadly and commonly used -- partly due to the success of Android phones -- that any problem becomes immediately, often overly amplified," said Charles King, principal analyst at Pund-IT.

Could frequent outages hurt Gmail's market share?

"Over time, I don't see the situation changing much -- though it could worsen if continuing growth results in more outages," King told us. "However, I doubt it will materially impact the company's success or position in this market."

He noted that users of e-mail as opposed to texting, instant messaging or other options tend to be older than the "youthful, free-spending consumers sought after by most vendors." And anyway, how much can people complain about kinks in a free service?

But losing access to e-mail seems less of a serious issue than the potential loss of documents, photos or other data Relevant Products/Services placed in the trust of Google via Drive.

Backing Up Is Essential

"The shift toward embracing cloud-like services such as Gmail often happens without much consideration of its long-term implications for critical communications functions (like e-mail)," King said. "Will Google Drive eventually crash? Probably -- that's the nature of the IT beast. The trick lies in determining how you can garner the benefits of that service while also mitigating the risk."

King added that in a world of increasingly multi-dimensional digital communication, its a mistake for users to entrust communication to a single technology, provider or outlet. "That way lies almost certain -- eventually, anyway -- failure."