Gmail typically blocks accounts when it detects high levels of activity within a short period of time. Gmail account temporary unavailable error usually occurs when activities such as receiving, deleting, or downloading large amounts of mails via POP or IMAP in a short period of time, sending numerous files/emails to many people, being logging into Gmail with multiple devices, and providing access to file-sharing that automatically logs into your Gmail account are detected. It usually takes one to twenty-four hours to reinstate the access.