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Email checks and security

Email Checking

All email to and from Plymouth Marjon University is subject to a number of checks, some of which may cause mail to be rejected, others of which result in a warning label being attached to the message before it is delivered.

Here is a summary of the checks made on your email.

Virus Checking - Any message detected of containing a virus or other harmful content is intercepted by the gateway and is not delivered to the intended recipient(s).  NOTE - This does not remove the need to run virus protection software on your PC. Although the gateway traps a large proportion of the viruses arriving at Marjon, there are other ways in which viruses can be spread, e.g. on floppy disk, by download from the Web, or by USB memory stick. Running an up to date virus checker on your computer is essential.


Attachment extension check – The contents of the attached file are checked and if recognised as a file having the potential to carry virus infections will be attachment will be removed.


Incoming email with a banned attachment type will have the attachment removed, and the remaining email passed to the recipient with an error message of the form:


Potentially dangerous attachments were identified and removed from this message.

If you try to send outgoing email with a banned attachment type from Marjon, it will rejected immediately. You will receive a "failure to send" message

Potentially dangerous attachments were identified and this message has not been sent.

Size Limit - Any message greater than 10Mb in size will be rejected.  This limit is to prevent mailboxes being filled quickly with large files, such as CD images.  If you need to transfer large files, please contact Computing Services.

Spam - Email content of incoming messages is checked by a hardened email appliance.  Emails are examined and assessed for spam likelihood; messages regarded as likely to be spam are quarantined.

Individual users can opt out of the spam checking by logging into their spam digest

            Sophos Email filter Self Service

and checking the “Disable all spam and offensive content blocking for my messages” box under the options menu.  However you will need other methods to control spam.


Unknown Recipients - If the mail address is not that of a valid Marjon email recipient, the message will be rejected as undeliverable.

This is an automatically generated Delivery Status Notification

Delivery to the following recipient failed permanently:

Technical details of permanent failure:
PERM_FAILURE: SMTP Error (state 13): 550 5.1.1 < >: Recipient address rejected: User unknown in relay recipient table


Originating address check If the originating email address of an incoming message is invalid (i.e. it would not be possible to reply to or return the message to the sender), the message is rejected as spam.

The anti-virus / anti-spam scanning system is part of the Sophos Email Appliance. The list of viruses recognised by this software is automatically kept up to date. As soon as a new virus is recognised by the Sophos maintenance team, details are sent out over the Internet and will be picked up by our Sophos Email Appliance.



Phishing Contents Check – The contents of email is checked for content that urges the recipient to click on links to malicious websites. These are often looking to collect your personal details on a fraudulent website.