We had an issue where we needed to change the location of the OU in a dynamic distribution groups that had moved from Exch 2003>2010>2013. We couldn't do it so we recreated a new distribution group with the same SMTP address. Now users are getting 5.1.1 errors when trying to send an email to the distribution list.
Here is the error:
IMCEAEX-_o=Wa-Nee+20Community+20Schools_ou=First+20Administrative+20Group_cn=Recipients_cn=nwhs@wanee.org
Remote Server returned '550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found'
I have found other posts that mention deleting the cached address in Outlook, but that has not solved my issue. Further reading leads me to believe it might have something to do with the legacy DN, but I don't know what to do to fix the issue.