Automated Email Bounce Backs – N3/HSCN based *.nhs.uk organisations sending automated emails to external recipients must monitor bounce backs. The higher the number of undelivered (bounced back) email from the Email Gateway, the higher the potential the Email Gateway would be categorised as a spamming source. It is vital that any automated mailing facility has a process in place to check and remove bounced email from mailing lists.
Compromised Accounts – A compromised account has the ability to send SPAM or malicious email. These emails (due to coming from a semi-trusted source on the N3/HSCN), may have been able to send several emails through the Email Gateway before being classified as SPAM (or malicious). It is important that local organisations monitor email locally for suspicious activity and ensure only warranted communications are sent to the Email Gateway.
Compromised Systems – Locally compromised systems can themselves be sources of spam or malicious email, or can lead to compromised accounts. All N3/HSCN based organisations should have security policies, antivirus, and system monitoring in place to minimise the likelihood of compromised systems.
Any sub-levels greater that 3 (as illustrated above), are not supported and may be rejected by the Email Gateway service.