After migrating mailboxes to exchange 2019 from exchange 2016 . Most of the mailboxes went to quarantine all of a sudden and databases went to dismount state and came back to mount state. We couldn’t bring the databases to a stable state. We realized its a bug in exchange 2019. Initially that it was a refs formatted disk was playing around we were wrong. Still I couldn’t believe this was the fix for the crazy issue.
Get-TransportConfig | fl *size*
You can check maxsendsize and maxreceivesize should not be unlimited. Set to 35 mb for example. It works seamlessly after that . Don’t ask me why. But it works like a charm.
Set-TransportConfig -MaxReceiveSize 35MB -MaxSendSize 35MB
Good to Have –
To Take out a mailbox from Quarantine –
Disable-MailboxQuarantine "Mailbox Name"
To place a mailbox in Quarantine –
Enable-MailboxQuarantine "Mailbox Name"
To check mailboxes which are in quarantine in a database
Get-Mailbox -Database "DBName" | Get-MailboxStatistics | Where {$_.IsQuarantine -eq $True}
