Hi,I was originally getting an error saying that mail could not be delivered to jbloggs@domain.com as two email addresses existed for the recipent. I went to the recipient and removed the email alias and tried to readd it but then it told me email address already exists.I have searched for this proxy address by every means imaginable i.e. exchange search, ad custum search, ldap,lde adsi edit but cannot find this ghost address anywhere. the only think I didnt try was the network trace suggested by one of the microsoft articles.ThanksPCeltic

Hi,Which version of Exchange do you use?- Do one more try with below articles to search or dump all email addresses for your whole domain and see if you find required proxy address.In Exchange 2007:EMS TitBit: Search/Find Email Addresseshttp://exchangeshare.wordpress.com/2009/01/19/ems-titbit-searchfind-email-addresses/In Exchange 2003 & 2007:HOW TO: Export all email addresses from a domainhttp://exchangepedia.com/blog/2005/09/how-to-export-all-email-addresses-from.html- Since you removed one email address, if you send mail now to jbloggs@domain.com, where does it get delivered per message tracking log? Or you get any error/NDR...- How many DCs you have in your environment? Check out if this is due to AD replication problem...Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Hi,Thanks for help. I have done the dump again, still no sign of the email addresses. I have now also deleted the account and mailbox and recreated both them and still no joy. It still thinks the email address is already there. If I type the email address into my to bar in outlook and do an ctrl+k it resolves to the correct name.If I send a mail from external in I get the following non-delivery report..Delivery has failed to these recipients or distribution lists: jbloggs The recipient's e-mail system can't process this message at this time. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message later, or provide the following diagnostic text to your system administrator. Diagnostic information for administrators: Generating server: mail01.theirdomain.com jbloggs@theirdomain.com #< #5.3.5> #SMTP# However right now sending an email internallt to jbloggs@theirdomain.com appears to be working now. Previously I was getting an error saying a message bounce between two servers was happening.I have three domains in one forest. I noticed that there was a complaint that the infrastructure master was on a gc for the root domain i have moved this now to an non gc server (windows 2003 sp2) but apart from this replication looks ok. in the domain i am having the account probelm there are 3 dcs.Still if I open the account jbloggs and try to add jbloggs@theirdomain.com it says email address already exists.I have spent the whole day at this now trying to figure it out :-(Thanks for helpP Celtic

Hi Amit,I managed to get this to work but oddly not using the normal method.....When I tried to email user jbloggs@domain.com I got a bounce back saying that email address didnt exist in organization. I then went to the properties of the user and as per the ndr their is no email address for jbloggs@domain.com. However when I tried to add the domain jbloggs@domain.com it complained that the address already existed.I then preceded to use ADSI edit and this allowed me to add the proxy address in manually i.e. jbloggs@domain.com. I was then successfully able to send email to the troubled recipient.Server details were:exchange 2003 sp2windows 2003 sp2The exchange organization consisted of 4 exchange servers 1 was a front endthere was 1 forest with 3 domainsthe troubled useraccount was in the root domain ( first domain installed)ThanksPCeltic

Cool... Thanks for sharing your solution here :)Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

It was a kindof roundabout solution as I never found out why the console thought the addresses already existed. This actually effected 2 users and adsi edit worked for bothCeltic

Yeh, because AD console is Exchange aware when Exchange management tools installed but ADSIedit.msc is not. Exchange would be taking information from the DC/GC where updated user information would not be available somehow but while using ADSIedit.msc, it would have been pointed to different DC/GC to update the user information.Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Hi Amit,I am afraid my cleint has just called informing me that the error has re-occurred. I get the error below when sending external and internal email to the recipientexternal mail in:There is a problem with the recipient's e-mail system. More than one user has this e-mail address. The recipient's system administrator will have to fix this.internal mail delivery:A configuration error in the recipient's e-mail system prevented delivery of this message. Two recipients are configured with the same e-mail address. Contact your administrator.I cannot find a duplicate address of either of the users anywhere in active directory. I have used all methods to search and have even used vb scripts to dump all the proxy addresses to a file and still no duplicates show. I have manually directed exchange to GC servers. I have also used the following to connect to each GC server and all proxy address for the user but no duplicates appeared! ldifde -f isisco.ldf -t 3268 -s isiscodc01.isisco.ie -r "(ProxyAddresses=jbloggs@domain.ie)Any ideas?I dont seem to have any replication problems between the domain controllers.ThanksCeltic