My problem is a bit strange and hard to explain, but im gone give it a try. Windows 2003 Enterprise Edition SP1 Plesk Reloaded 7.5.2 MailEnable Standard 1.8 In plesk i've got 2 clients: Client1 and Client2 Client1 has a domain domain1a with a mail account vincent@domain1a, with two aliases info@domain1a and admin@domain1a. Mail for the account vincent@domain1a is redirected to email@example.com. Client2 has a domain domain2a with a mail account catchall@domain2a. Mail preferences "Mail to nonexistent user" is set to "Catch to address: catchall@domain2a" Client2 also has a domain domain2b. No mail accounts are set for this domain. Ive send the following mails with two different mail account on two different servers. Both gave the same results: To address -> recieved by info@domain2a -> firstname.lastname@example.org admin@domain2a -> email@example.com vincent@domain2a -> catchall@domain2a anyothername@domain2a -> catchall@domain2a info@domain2b -> firstname.lastname@example.org admin@domain2b -> email@example.com vincent@domain2b -> bounce anyothername@domain2b -> bounce I also tested this for other domain of Client2 who have no mail accounts set. All gave the same results as for doamain2b. The problems started from the moment the two mail aliases where added for vincent@domain1a. Client1 has a total of 70 domains. All mail account work normal (except for domain domain1a). Client2 has a total of 15 domains. None of the have a mail account setup (except for domain domain2a) I haven't tryed to remove and readd domain1a or domain2a, because I want to know why this is happening. Help!