A number of Google+ users on Saturday have received multiple email notifications, even when users have requested that those notifications be turned off. Some users have reported via Twitter that they have received as many as 50 notifications for just one friend being added to their Google Circle.
Twitter user @aeazel reports the following:
Google+, I just turned off notifications today. Why did I receive 30 emails about the same person adding me to a circle?
Gmail accounts are starting to resemble something similar to this (thanks @dustinbrewer):
While the cause is not yet known, a Twitter user Daniel Obenshain has said that turning off notifications and re-enabling them again will fix the issue.
Later on Saturday. Google's Vic Gundotra, the head of the Google+ division, posted an apology about the multiple notifications on his Google+ page stating,
Please accept our apologies for the spam we caused this afternoon.
For about 80 minutes we ran out of disk space on the service that keeps track of notifications. Hence our system continued to try sending notifications. Over, and over again. Yikes.
We didn't expect to hit these high thresholds so quickly, but we should have.
Thank you for helping us during this field trial, and once again, we are very sorry for the spam.