Hi all, I deleted a user from my exchange 2007 setup and when I tried adding him again, I have ran into all sorts of issues. My main problem is as follows: I can't send him any e-mails from internal mailboxes. The error is as follows: Delivery has failed to these recipients or distribution lists: Jose Clua The recipient's e-mail address was not found in the recipient's e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator. _____ Sent by Microsoft Exchange Server 2007 Diagnostic information for administrators: Generating server: exchange.ccl.local IMCEAEX-_O=CHAMPION+20COMPRESSORS_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP +20+28FYDIBOHF23SPDLT +29_CN=RECIPIENTS_CN=Jclua@championcompressors.com.au #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ## I can, however, send him e-mails when replying to e-mails that mailbox sends. I tried looking through google for that error (Delivery has failed to these recipients or distribution lists) but the outcome has not really been that helpful. Please help!! I don't know what else to do .. Thanks, Diego.