Error #103 means MaxBulk Mailer was unable to resolve the address that was specified. A prime example of this would be a mistyped IP address, or a domain name of an unknown or unreachable host.

On the Windows operating system, error 103 can be produced by an Anti-virus software. As an exemple McAfee has a port blocking that doesn't block Outlook Express, but would block MaxBulk. The software can be set to allow MaxBulk Mailer though. A similar issue can be produced by Norton Anti-virus as well. You can simply uncheck virus detection on outgoing e-mails.