Tag: exchange

Happy New year 2020. I wish you more progress this year from where you left off last year. Now let’s dive right to our topic on MailNonUniversalGroup distribution list. So i had a case where users where complaining of not receiving emails sent to a distribution list. After several minutes tracing the messages, it came to a halt with the following interesting details from the trace log:-

——–

Source : ROUTING
EventId : DROP

RecipientStatus : {[{LED=250 2.1.5 RESOLVER.GRP.Expanded; distribution list expanded};{MSG=};{FQDN=};{IP=};{LRT=}]}

——–

Some further digging and here is what i found for the distribution group that was not receiving emails:-

Get-DistributionGroup "nameofmydistributionlist" | fl recipienttypedetails

RecipientTypeDetails : MailNonUniversalGroup

Result shows my distribution group was of type: MailNonUniversalGroup

Further checking on when this group was first created in AD, shows far back as of 2012, and this must have been when it was migrated from previous legacy exchange 2003 to exchange 2010 but was not upgraded to a universal group at that time.

Microsoft recommends to convert all legacy exchange distribution groups to “universal” groups for use on Exchange 2010/2013/2016/2019 especially if you want to have all the features of distribution groups included.

In my case the distribution group members where on office365 and they needed to receive external email sent to the email address of the distribution list.

To solve, change the distribution group from MailNonUniversalGroup to Universal, I did this via exchange powershell:-

Get-DistributionGroup "nameofmydistributionlist" | Set-Group -Universal

wait a few minutes for replication and check again using:-

Get-DistributionGroup "nameofmydistributionlist" | fl recipienttypedetails

RecipientTypeDetails : MailUniversalDistributionGroup

It has now been converted to MailUniversalDistributionGroup

Now we can receive emails sent to the distribution list without any issues.

Tip: To do this in bulk for all your distribution groups that was just migrated over from legacy exchange versions 2003/2007, you can use the following command which will change all mailnonuniversalgroups to universal:-

Get-DistributionGroup -ResultSize unlimited -RecipientTypeDetails mailnonuniversalgroup | Set-Group universal

and then to apply the upgrade :

Get-DistributionGroup -ResultSize unlimited | Set-DistributionGroup -ForceUpgrade