The message was sent to a distribution list ‎(DL)‎ - Microsoft Community

hi all,

i posting question have faced issue last week, migration done exchange 2007 o365.

there 1 distribution list in on prem & in o365 group (synced aadc). 1 migrated user send email dl before & after migration, strange thing that, before migration ok, after migration user got message as

"

delivery has failed these recipients or distribution lists:

*** email address removed privacy ***

 this message has many recipients. microsoft exchange not try redeliver message you. please try resending fewer recipients, or provide following diagnostic text system administrator".

*** email address removed privacy ***
#550 5.5.3 resolver.adr.reciplimit; many recipients ##

i have checked same message id in o365 message trace & found following...

8/16/2017 11:17:55 am

receive

message received by: db4pr05mb397

message received by: db4pr05mb397

8/16/2017 11:17:56 am

expand dl

the message sent distribution list ‎(dl)‎ expanded recipients of dl.

the message sent distribution list ‎(dl)‎ expanded recipients of dl.

8/16/2017 11:17:59 am

drop

reason: [{led=250 2.1.5 resolver.grp.expanded; distribution list expanded};{msg=};{fqdn=};{ip=};{lrt=}]

reason: [{led=250 2.1.5 resolver.grp.expanded; distribution list expanded};{msg=};{fqdn=};{ip=};{lrt=}]

could please tell me reason of why dl  got expanded before email reaching on-premise server.

this become issue since migrate users, please provide feedback on this.

regards

bg

hi bg,

reply. please update information @ convenience.

best regards,
shyamal

Office / Office 365 for admins / Upgrade to Office 365  / Office 365 for business