old email cache issue

Have you tried to add an X.500 proxy address through the Exchange Management Console?

Source:  https://www.simple-talk.com/sysadmin/exchange/exchange-e-mail-addresses-and-the-outlook-address-cache/

yes, we already did this, but still getting issue

still there is issue, one more thing, if i can see the current legacy DN that is new and it is not in email address as a x.500 address

so anything need to be done with current legacydn ??

issue is when user trying to replying his old emails, he getting NDR

Thanks,
andy

Have you added the old legacyExchangeDN X.500 address to the new mailbox as a proxy address?

yes.. i have added that, but still if user reply to any new email of that user, they get NDR
and user tried to send email to himself from webmail.. still NDR

Also we can see disconnected mailbox is still showing in disconnected state

exchange 2013

Permanently delete a disconnected mailbox

Use the Shell to permanently delete a disconnected mailbox

There are two types of disconnected mailboxes: disabled and soft-deleted. You must specify one of these types when running the cmdlet to permanently delete the mailbox. If the type you specify doesn't match the actual type of the disconnected mailbox, the command fails.

Run the following command to determine whether a disconnected mailbox is disabled or soft-deleted.

Get-MailboxDatabase | Get-MailboxStatistics | Where { $_.DisplayName -eq "<display name>" } | fl DisplayName,MailboxGuid,Database,DisconnectReason

Select allOpen in new window

Source: https://technet.microsoft.com/en-us/library/jj863440(v=exchg.150).aspx

Check with the user that the content inside the disconnected mailbox is of no practical use and the disconnected mailbox can be
removed.

so do you think, after purge the disconnected mailbox, will it Resolve  the issue permnanetly

means if any user reply to any old email of that user, will not get the NDR ?

i ran this command, but not giving any result, But in EAC i can see the mailbox in disconnected state.,
i also fetched the legacydn of that mailbox in Powershell using this

Get-MailboxStatistics -Server chlte312 | ?{$_.DisconnectDate -ne $null -and $_.DisplayName -like “craig kelly”} | Select LegacyDN

now after mailbox get purged from disconnected mailbox.

i checked with user, and from OWA issue resolved, when replying any old email before disconnected . it works now
but from outlook, still issues, getting NDR

i have cleared cache too, but still same.. on new email it works, but old email reply not works

Any suggestion

If OWA works, the problem is on the client side.

Request a copy of the NDR and the message of the sent mail and inspect the header.

Thanks