There're two companies. And if the user in company,(anyone with that domain) sends mail to the user in another company, then the user will get the failure report mail with the message like below, RCPT Error transferring to [rcpt domain name]; SMTP Protocol Returned a Permanent Error 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.5.3 - chkuser) RCPT Host is running exchange server. and I want to know, where they can set for 'allowed rcpthosts'. All the user in one company cannot send to people in other company, though they are having close relationship. So, I want to fix this problem in a short time. But, I hardly know about Exchange server settings. Please let me know anything related to this message.

Hi, This is what i found... The error, "553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)", means that you are trying to send email using the wrong smtp server. Smtp related errors may have different numbers and slightly different wording, eg, "Relay access denied for...", but are all related to the same problem. The smtp server that you use to send email is not determined by who hosts your email, but rather is a service of your Internet connection provider. All ISP's provide their customers with smtp servers, regardless of their email address. One of the most important reasons for doing this is so spammers cannot connect to an unauthorized smtp server and use it to send mountains of spam. Occasionally, spammers find these "open" systems and flood them with mail. These systems are known as "open relays" and are the result of careless configuration by the operator. Clients commonly see this error when they configure their PC at work, then try to use the same configuration at home, where the Internet connection is provided by a different ISP. The fix for this situation is to change the smtp server in the mail client to match the one provided by the ISP. Rowen TechNet Community Support

On Thu, 1 Dec 2011 11:56:20 +0000, JOOO85 wrote: > > >There're two companies. > >And if the user in company,(anyone with that domain) sends mail to the user in another company, then the user will get the failure report mail with the message like below, RCPT > >Error transferring to [rcpt domain name]; SMTP Protocol Returned a Permanent Error 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.5.3 - chkuser) That status message didn't come from an Exchange server. The "other company" is using a SMTP relay and it hasn't properly configured to accept (and relay) e-mail sent to the domain. Another explanation is that the server you're sending the e-mail to isn't the right one. Your DNS may have cached a bad query result. >RCPT Host is running exchange server. and I want to know, where they can set for 'allowed rcpthosts'. > >All the user in one company cannot send to people in other company, though they are having close relationship. > > > >So, I want to fix this problem in a short time. But, I hardly know about Exchange server settings. Please let me know anything related to this message. --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP