Earlier today, subscribers to Google's Project Fi may have run into a problem sending or receiving SMS or MMS messages. The brief outage appears to have started this morning, with reports of resolution emerging around 3:50 PM Eastern Time (12:50 PM Pacific). SMS and MMS are now reported as working by many, though it may not be resolved for all subscribers and you may run into additional delays as a result of a backlog of messages waiting to hit your phone.
Project Fi is no stranger to outages, though the company's support has always been quick to respond to problems. In many cases, these issues carry over from a problem with one of the other networks Project Fi uses for service, since it's an MVNO. Those carriers include T-Mobile, Sprint, and US Cellular. So far, none of them seem to have any widespread reports for problems for that period, though.
One of the Project Fi community managers made a statement related to the outage on Reddit a few hours ago:
We are currently aware of an issue where SMS text messages are not sending or being received.
Please continue to share any additional information with us here. We'll keep you posted with updates.
Project Fi Community Manager
Many reports indicate that the issue has now been resolved, but some subscribers may still be affected. Project Fi has yet to state that the problem is officially fixed, and the Project Fi Help Center still has a warning for ongoing SMS/MMS issues.
As with all things Google, YMMV