RecipientHasNoMdb 420 4.2.0 Recipient deferred because there is no Mdb

Question

_{Wednesday, January 16, 2019 9:07 AM}

Hi,

I have a problem with my Exchange 2016 Server, i have 1 exchange server and no Office 365.

I have 2 users where mail work perfectly, but when i add new user, reception of new external mail not work.

I have {LED=420 4.2.0 Recipient deferred because there is no Mdb} return.
I see in TransportRoles\Logs\MessageTracking this message :

2019-01-16T08:16:09.431Z,,SERVEUR2012,,,RecipientHasNoMdb,,ROUTING,DEFER,365072220167,<2.1.11.1101029949.8337862.52481435665@****.fr>,4759ade1-94b8-4836-7bbf-08d67b88c2ee,yannick@*******,'[{LED=420 4.2.0 Recipient deferred because there is no Mdb};{MSG=};{FQDN=};{IP=};{LRT=}]',32487,1,,,[Nouveau service en ligne] Configurez et commandez votre grille de ventilation Renson,infos@*******,infos@*****,2019-01-16T08:31:09.431Z,Incoming,,,,S:DeliveryPriority=Normal;S:AccountForest=*****.local,Email,3a82c0fa-4ca6-4c13-54af-08d67b8adede,15.01.1591.012

I dont understand why.

Any help, thanks you.

All replies (2)

_{Thursday, January 17, 2019 6:45 AM}

I have 2 users where mail work perfectly, but when i add new user, reception of new external mail not work.

Hi Bruno,

I'm a little confused about the words above. How did you add new user? cannot receive mail from outside only ?

Could you show us an example to explain this in details? 

Moreover, I also find a similar thread for your reference, please try the solution and check if any helps:

Recipient deferred because there is no Mdb

Solution:  add email in targetaddress attribute in active directory

Best Regards,
Niko Cheng
Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact [email protected].

Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

_{Friday, February 1, 2019 1:47 AM}

Hi Bruno,

Does the suggestion above help? If you have any questions or needed further help on this issue, please feel free to post back. If the issue has been resolved, please mark the helpful replies as answers, this will make answer searching in the forum easier and be beneficial to other community members as well.

Thanks for your understanding.

Best Regards,
Niko Cheng
Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact [email protected].

Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.