Powershell – Exchange’s New-MailboxExportRequest behaves strangely with DateTime parameters to ContentFilter

In the Exchange Management Shell New-MailboxExportRequest

It will request a filepath, which is relative to the Exchange server holding the mailbox, and must be accessibly by the same user that the store.exe process is running as (typically the machine account). It will also ask for the Mailbox, specify by the alias.

You can get an update of what it's doing with Get-MailboxExportRequest; which can be piped to Get-MailboxExportRequestStatiscs for more details.

And cleanup after your export when it's done with Remove-MailboxExportRequest. It's usually best to run this as Remove-MailboxExportRequest -Status Competed so any failed or pending requests are left to run or be examined.

Edit:
That error means that the Exchange Trusted Subsystem doesn't have read/write access to the path you specified.

Edit 2:
That error apparently can also be generated if you don't have permission to import/export. Check your Exchange Role and be sure you have those permissions. - Thanks to jshin47 for that.

Use the Get-Date cmdlet!

The snippet below will check what month it is, subtract 1 and export all messages to your .pst file

$endDate = Get-Date -Day 1 "00:00:00"
$startDate = $endDate.AddMonths(-1)
$month = "{0:D2}" -f [int]$startDate.Month

# Convert dates to short date strings
$endDate = $endDate.ToShortDateString()
$startDate = $startDate.ToShortDateString()

New-MailboxExportRequest -ContentFilter {(Received -ge $startDate) -and (Received -lt $endDate)} -Mailbox "MonitorMailbox" -FilePath "\\Server\backup\EmailLog\MonitorMailbox 2013-${month}.pst"

while(!(Get-MailboxExportRequest -Mailbox "MonitorMailbox" -Status Completed))
{
    #Sleep for a  few minutes
    Start-Sleep -s 300
}
Get-MailboxExportRequest -Mailbox "MonitorMailbox" -Status Completed | Remove-MailboxExportRequest

Get-Mailbox -Identity "MonitorMailbox" | Search-Mailbox -SearchQuery "Received:'${startDate}'..'${endDate}'" -DeleteContent

Simple run this once a month to get the last months emails archived