In September of last year, Microsoft detailed a bunch of features for Teams that introduced enhancements to its video calling and chat features, among others. The announcement also made mention of upcoming support for offline sending on desktops, though there was no specific date then for its rollout.
Now, an update posted to the Microsoft 365 roadmap website has revealed when that feature will become available. Later this month, Microsoft Teams will add the ability to queue messages when a device goes offline. That means your messages will still be sent later even when you fall off the grid, provided your device manages to go back online within 24 hours.
However, unsent messages that are queued for more than 24 hours will no longer be sent even if the device resumes internet connection. Instead, you will receive an alert prompting you to either delete or re-send that message.
This capability is only part of the update's first phase. In the second phase, you will be able to edit an unsent message while it's still in queue (via Petri). This capability will roll out in mid-February.
Currently, Teams displays a "failed" status for messages you try to send while your device is offline. The new experience comes in handy for situations where you have an unstable connection.