There is no standard way of migrating an Exchange dynamic distribution group to a standard distribution group.
I used powershell to automate this task.
- fill the variables with the needed information or via a csv and load the data into powershell
- List existing members of the dynamic group
- Save the members to a variable
- rename the old DG
- Create the new DG
- Add the members to the new DG
- Check the new DG
First connect to Exchange online Powershell
$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session -DisableNameChecking
#Remove-PSSession $Session
#Dynamic distribution group which neede to be migrated
$DG = "Team-Testgroup"
$DynamicDG = Get-DynamicDistributionGroup $DG
#variable which is used to rename the Dynamic distribution group
$NewNameDG = $DG+"-old"
#list the Existing members of the Dynamic DG
Get-Recipient -RecipientPreviewFilter $DynamicDG.RecipientFilter
start-sleep -s 10
#Save the Members in a Variable
$DGMembers = Get-Recipient -RecipientPreviewFilter $DynamicDG.RecipientFilter
#rename the old Dynamic Distribution Group group name
Set-DynamicDistributionGroup -Identity $DG"-DL@****.onmicrosoft.com" -Name $NewNameDG -DisplayName $NewNameDG -Alias $NewNameDG -PrimarySmtpAddres $NewNameDG"@****.onmicrosoft.com"
Start-Sleep -s 5
#Create a New Distribution Group
New-DistributionGroup -Name $DG -Alias $DG -PrimarySmtpAddress $DG"@domain name"
#Get-DistributionGroup -identity $DG"@****.onmicrosoft.com"
#Get-Mailbox -identity $DG"@****.onmicrosoft.com"
#Adding the DynamicDistributionGroup members into the New Distribution Group
$DGMembers | foreach{Add-DistributionGroupmember $DG –Member $_.Name}
#Verifying the members of the New Distribution Group
Get-DistributionGroupMember $DG