This feature is only available in Akeeba Backup Professional.
You can configure Akeeba Backup so that it automatically uploads backup archives to remote storage, such as Amazon S3, Dropbox, (S)FTP servers etc. However, this upload may fail. You may have the wrong or expired login credentials. There might be a temporary issue with your server, the network, or the remote storage provider. The remote storage provider may have run out of space / you may have reached a quota. And so on and so forth.
Assuming that you have not enabled the Fail backup on upload failure option, a backup where only the upload to remote storage failed to complete is NOT considered a failed backup. This is because you still have a backup archive. You need to go to the Manage Backups page and try to reupload the backup archive. If that fails, you need to check the connection information and resolve any issues until the reupload works.
Of course, being able to do that for scheduled backups means that you need a way to be notified about backups whose upload to remote storage failed. This is exactly what the check for failed uploads feature does.
You can use it to automate the check for backups with failed uploads and have it email you when it detects that the latest backup has failed.
This feature is only available in Akeeba Backup Professional.
Requires the Enable Legacy Front-end Backup API (remote CRON jobs) option to be enabled in the component's Options, Frontend tab.
The front-end backup upload failure check feature lets you perform an unattended, scheduled check for backups which failed to upload to remote storage.
Before beginning to use this feature, you must set up Akeeba Backup to support the front-end backup option as explained in the relevant section of this documentation.
The URL to use to trigger the front-end backup failure check feature is
http://www.yoursite.com/index.php?option=com_akeebabackup&view=Checkupload&key=YourSecretKey
where YourSecretKey is the Secret Word for front-end backups, as configured in the component's Options page.
Please note that YourSecretKey must be URL-encoded. You can use an online tool like http://www.url-encode-decode.com or simply consult the Schedule Automatic Backups page.
If you want to automate the check you can schedule this URL just like you would a front-end backup URL. Furthermore, the front-end backup failure check URL does NOT use redirections. Therefore it can even be used with hosts and services which do not follow redirections.