Some users of the popular Gmail service faced difficulties while trying to access their accounts on Tuesday, encountering a “Server 502 error”. The error did not affect all users, with most subscribers able to use Gmail without any glitch.

The affected subscribers were asked to re-login after 30 seconds.

Google published the following message on their Apps Status Dashboard, apologising for the break in services: “We're aware of a problem with Google Mail affecting a significant subset of users. The affected users are unable to access Google Mail. We will provide an update by May 11, 2010 11:45:00 AM UTC+5:30 detailing when we expect to resolve the problem. Please note that this resolution time is an estimate and may change.”

This message was followed by an update which read, “The problem with Google Mail should be resolved. We apologise for the inconvenience and thank you for your patience and continued support.”

According to Wikipedia, a “Server 502 error” points to a case where there is a miscommunication between the upstream server and the server - also referred to as the gateway or proxy - which is used to fulfil the request made by the user through his web browser. The gateway contacts the upstream server to process the request to access the site (www.gmail.com). However, Google has not released any official reason for the disruption of services.

It may be noted that some users route their company email to Gmail, thereby using Gmail as their primary email account for official purposes. Outages to Gmail result in severe difficulties for these users.