Thanks for your help. Do you think then that it could be that the recipient subscribes to a spamcop email service? As you say, our domain doesn't seem to be blacklisted and the only time I get this message is when we try to email this company. Today was our first contact with them; we replied to their business enquiry and after emailing them twice within an hour or so I'm wondering if we just need to be whitelisted at their end? P.S. I meant to add that it is only our exchange server email address which is being blocked. If I change to a different account with direct access to our internet domain pop3 we can get through with no problems.
Not sure if this is the right forum as I'm new here, but I got the following meesage when trying to send email to a client (I've substitued their email address): Your message did not reach some or all of the intended recipients. Subject: Excel Courses Sent: 03/06/2008 18:05 The following recipient(s) cannot be reached: info[at]client.co.uk on 03/06/2008 18:05 There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. <cyberstudios.co.uk #5.5.0 smtp;550 Rule imposed as PaulBrown[at]cyberstudios.co.uk is blacklisted on SpamCop (see www.spamcop.net)> I only receive this message when emailing this particular recipient. Is the email being blocked at their end or mine? Thanks! Paul