No announcement yet.

550 Relay not permitted error

  • Filter
  • Time
  • Show
Clear All
new posts

  • 550 Relay not permitted error

    We have a client who is running Exchange 2003. Their remote locations user the server as a POP/SMTP server to send and receive email. One of their locations was running fine until last week when they changed their ISP. Now when this site tries to send email using Outlook via their SMTP mail server, they get the error "550 Relay not permitted".

    What is the cause of this error and how can I solve it? Why would changing ISP cause this error? The ISP was not changed where the server is located, only at the remote location.

    Thank you for your help.

  • #2
    Re: 550 Relay not permitted error

    It could be that the remote site's ISP ip address was set on the Exchange SMTP virtual server as allowed to relay. When changing ISP's they got a new ip address.

    Note that if you must allow relaying, this is not the best method. I would recommend switching to authenticated relaying.

    Also, if the remote site is part of the AD domain and the users at the remote site have user accounts in the domain, why do you have them using POP/SMTP instead of using Exchange natively?