#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ## exchange 2010

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We Recently moved (like a month or so ago) from exchange 2007 to exchange 2010. All of the exchange 2007 servers have been uninstalled and shut down. We are using an edge transport server and a " mailbox" server.

We have one user receiving this error message sending from his MACbookpro AND from OWA. He has this issue when sending to several different email addresses within the company, not just one.


#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##

We've manually updated the OAB on the server and that hasn't resolved the issue either.

Any guidance or insight regarding this matter would be greatly appreciated.

Thank you

Heather Moreton

Appriss, Inc


Leif Pedersen [MVP]


I see a similar problem when user1 sends a mail to user2 and caches the name of user2 in Outlooks cache file. If user2 then for some reason is recretade with a new mailbox the user2 legacyexchangedn will be new and cause problems next time user1 tries to mail the user.

Try to have the user make sure that he selects his recipients from the address book instead of the cache just to make sure.

You can correct this problem either by deleting user1's cache or by adding a new legacyexchangedn address as a X500 address to the users he has problems sending to. You can deciffer the address from the above with a little help from a working legacyexchangedn.


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