emails bouncing back from recipients

[terlan]

We are getting numerous emails coming back to us from recipients with the following error text when sending from addresses on our windows server

Subject: Message Delivery Failure
>
> MailEnable: Message could not be delivered to some recipients.
> The following recipient(s) could not be reached:
>
> Recipient: [SMTP:namehere@peterborough.gov.uk]
> Reason: 554 Transaction Failed Spam Message not queued.

But if the exact same email is sent from another email account not on the server (hotmail, virginmedia, bt etc) the email reaches the recipient without a problem.

Has anyone encountered a problem like this before or could perhaps shed some light on the issue?

[Rock]

There are several reasons for this type of error to pop up all of a sudden. Compromised system being one of them, which needs to be cleaned in order to send email through this server. Incorrect/improper mail server settings can be one of the other reasons.. or maybe your IP is blacklisted in some spam database engines. Not having rDNS setup on the IP address too can cause this. If you open up a ticket with our Windows Support Dept with the necessary details, we can have the server checked thoroughly for all the possibilities & get this sorted ASAP.

[terlan]

thanks I'll open a support ticket today

[Rock]

thanks I'll open a support ticket today

You're welcome..