A Gmail glitch that took about 10 hours to fix and hit close to 50 percent of the webmail service's users has been fixed, ending one of the longest, most widespread Gmail disruptions in years.

Affected users endured email delivery delays and difficulties downloading attachments due to a still unexplained bug first acknowledged by Google at around 10:30 a.m. U.S. Eastern Time Monday. The company declared it patched at 10 p.m.

On its Google Apps Status site, the company pegged the start of the problem at close to 9 a.m. and its resolution at 6:30 p.m.

On Tuesday, Google offered more details about the cause of the problem and the steps it's taking to prevent it from happening again.

The cause was a "very rare" dual network failure, which brought down two separate, redundant network paths, according to a blog post from Sabrina Farmer, senior site reliability engineering manager for Gmail.

"The two network failures were unrelated, but in combination they reduced Gmails capacity to deliver messages to users," she wrote.

Over the next few weeks, Google staffers will work on bulking up network and backup capacity for Gmail, as well as on making Gmail's message delivery more resilient in the event of a network crash, according to Farmer.

"Finally, were updating our internal practices so that we can more quickly and effectively respond to network issues," she wrote.