Updated Exchange Online function to use EXO V2 and MFA !

1.6 - Replaced legacy Exchange Online connection function with modern Exchange Online Management V2 connection function (Connect-ExchOnlineV2)
Also fixed a DiscoveryMailbox test logic issue (didn't update progress bar label in case DiscoverMailbox does not exist + output message didn't make sense at all - bruh what was I thinking ?? )

eDiscovery Tool for Exchange 2010, 2013 and 2016

Fix:

Fixed encoding of the file that messed up the whole script when downloaded.

Here's the version history:

1- Complete version, GUI bilingual French/English (Powershell underlying console in English), switch to connect to On-Premise or O365 Exchange
1.1 - Added a check on Search-Mailbox -DeleteContent parameter and grey out "Delete Mailbox" if we don't have the right to Delete
1.2 - normalized strings
1.3 - Added test on Discovery Mailbox - if it doesn't exist, inform the user - except for Search-Mailbox -EstimateOnly, which doesn't need a Discovery Mailbox.
1.401 - added and optimized the Welcome/Readme text in English and French
Fix: removed Get-Credentials -Message as the "-Message" parameter doesn't work on Powershell v2.0 (Windows 2008 R2 Powershell).
1.402 - removed "check spelling of Discovery mailbox" when error when one mailbox is not found. Discovery Mailbox check is done separately
1.5 - Added logging into a file
LOG File is always created under User's profile \ Documents folder. Log file name hard coded (search for string:
"$($env:userprofile)\Documents\eDiscoveryLog.txt"
Can always change the log file destination by using the "-LogFile" parameter after each call of the "Log" function
1.5.1 - case Source Mailboxes to search in is blank
Updated Update-CmdLine when SourceMailboxes is blank
Add confirmation to continue searching all mailboxes (Continue ? Yes/No)
Updated btn_Run function -> using the command line built by Update-CmdLine function (reusing $richTextBox.Text) - NOTE: btn_Run has additionnal tests
1.5.2 - FR and US translation for "search in all mailboxes" confirm box.
1.5.3 - added filter on Get-mailbox to exclude search in Discovery Mailbox when using Search-Mailbox
1.5.4 - fixed Right to Delete variable $RightToDelete - was set in the Test-ExchCx function but was local to
this function only. Fix : make it global for the whole application.
1.5.4.1 - 09 MAR 2017 - changed a bit the Log function to add default string in case no String parameter is specified
1.5.4.2 - 09 MAR 2017 - removed the "-LogLevel full" if "-DeleteContent" is checked...

1.5.5 - Review code and remove a few useless comments before publishing
1.5.6 - Adding suggestions (no code modification) - Publishing version
18AUG2017 - incrementing minor version to get rid of minor-minor version
Suggestion : add time in date selection for searches.
1.5.6.1 - fixing Get-Mailbox -REsultSize Unlimited | Search-Mailbox / changing to Get-MailboxDatabase | ForEach {Get-Mailbox $_ -resultsize Unlmited | Search-Mailbox blablablabla}
1.5.7 - Change to Delete e-mails option using Search-Mailbox : instead of loading all mailboxes of an Org and piping all on Search-Mailbox,
I load all MAilboxDatabases first, and using ForEach ($Database in $DatabaseList) {$MBXBatch = Get-Mailbox -Database $Database; and piping $MBXBatch to Search-Mailbox instead.
1.5.7.1 - Encoding issue - re-saved the file with UTF-8 encoding - French accents were messing up with the whole script

eDiscovery Tool for Exchange 2010, 2013 and 2016

This is the release v1.5.7 of the eDiscovery tool