Your message couldn't be delivered because the recipient's email system reported the following error: '550 Message exceeds size limit (#5.3.4)'.
It's possible it's a temporary issue with their email system. Try to resend the message. If the problem continues, contact the recipient by some other means (by phone for example) and ask them to tell their email admin about the problem. Be sure to give them the error above, as it will better help them diagnose the problem.
For Email Administrators
This error is being returned by the recipient's email system but it doesn't include a valid, specific, enhanced SMTP status code, making it difficult to assess exactly what the problem is. Please carefully examine the error reported by the recipient's email system to help diagnose and troubleshoot the problem. Only the recipient's email admin will be able to fix this.
spamserver.net gave this error:
Message exceeds size limit (#5.3.4)
Note: nothing has changed on the server and we've not had this limit in the past, couple things:
1. checked with the ISP confirmed no restrictions.
2. New firewall however don't believe it's the problem. If anyone has any info regarding email restrictions with a Sonic Wall firewall let me know.
SBS2008 / Exchange 2007