Although it isn’t experiencing a complete outage as it was earlier today, numerous Gmail users are currently reporting substantial problems with the email service.

Several users indicate that Gmail is functioning with considerable slowness, and others are encountering frequent error notifications. A journalist from TechCrunch, for example, observed that emails sent to Gmail addresses were immediately being returned to sender, with Gmail’s system providing an error message stating “550-5.1.1 The recipient email address could not be found.”

Google has acknowledged the difficulties on its system status page, stating at 1:30 PM Pacific Time that a “significant” portion of its user base is affected:

A subsequent update at 2:30 PM indicates that Google’s engineering teams are “actively working to resolve this problem”; at 3:30 PM, the company projected a resolution time of 4:00 PM, but cautioned that this estimate is subject to change.

Update, 4:15 PM Pacific: Google now reports that the issues have been successfully addressed.

In the meantime, secure email provider ProtonMail posted on social media that the email return issue previously described is extensive, with a large number of emails to Gmail accounts failing to deliver:

If you are attempting to send a critical email to a Gmail user, it is advisable to postpone sending it until the situation is completely resolved; if you have recently sent an email, it’s prudent to verify its successful delivery.