SMTP communication problem smtp;550 - emails bouncing back
My customer recently had some emails bouncing back with the error that stated "There was a SMTP communication problem with the recipient's email server. Please contact your system administrator" and "<Customer.com #5.5.0 smtp;550-(Customer.com) [1.2.3.4] is currently not permitted to relay through>". I dont have a MX record pointing at the Exchange server on the SBS 2003 R2. I also dont have a smart host setup at this time? But we do have a static ip on the router for the outside and also have access to our dns records at out host. Can anyone tell me a proper way to deal with this problem? Thanks.
Re: SMTP communication problem smtp;550 - emails bouncing back
Can you try to confirm whether the recipients email address were typed properly, for an examply: not using single quote sign or so. Have you tried using mxtoolbox.com to check your public ip if it is listed in the blacklist or not? Can you also try to check whether you configured an external DNS server in the SMTP virtual server, if so, then try to please remove it and make some tests.
