1012MSExchange Store Driver Submission Error (Info) Application The store driver failed to submit eventID mailboxID MDBID and couldn't generate an NDR due to exception Microsoft.Exchange.MailboxTransport.StoreDriverCommon.InvalidSenderException
This is your Exchange Server telling you that it is unable to send an approaching mailbox storage limit message to a particular mailbox.
This can be resolved by setting the regional language settings for all your mailboxes that do not have an assigned regional language setting.
You can find out what your regional language settings are for your mailboxes by running this command from Exchange Shell:
Get-Mailbox -ResultSize Unlimited | Get-MailboxRegionalConfiguration
Use the following command from an administrative instance of Exchange Shell to change them all to English:
Get-Mailbox -ResultSize Unlimited | Get-MailboxRegionalConfiguration | Where {$_.Language -eq $null} | Set-MailboxRegionalConfiguration -Language en-US