Sending attachments

Sending files via email

It is now common to send files via email. Unfortunately, this practice is also a common way to spread viruses. We automatically scan, and in most cases restrict the files that can be sent as an attachment, thus limiting the threat from email based viruses. This page advises what attachments can and cannot be sent via your university email account.

What files can I send as an email attachment?

In order to limit our vulnerability from email based virus attacks attacking the network, we automatically block and remove any email sent or received with any of the following file extensions:

  • .bat
  • .chm
  • .cmd
  • .com
  • .cpl
  • .exe
  • .lnk
  • .pif
  • .reg
  • .scr
  • .shs
  • .vbs
  • .vbe
  • .wsf

In addition, any .ZIP files that are sent as an attachment, and contain any of these file types will also be automatically removed, and encrypted, unreadable or corrupted zip archives are also blocked.

The blocking and removal will occur on transfers between any of our servers, or from and to the internet.

How do I know if a file attachment has been blocked?

If you attempt to send, or are sent an email with one of the file extensions listed, both you and the sender of the email will be sent an email stating the message

Antigen for Exchange found winmail.dat->nameoffile.EXE matching FILE FILTER= *.exe file filter. The file is currently Removed. The message, "File Test", was sent from Bloggs, Joe and was discovered in SMTP Messages\Inbound located at Liverpool John Moores University/JMU/EXCH1.

How do I send a file with one of the blocked extensions?

We are aware that there may be times when it may be necessary to send a file via email with one of the blocked file extensions, for example when submitting coursework to a course tutor.

In order to allow this, we have implemented a .jmu file extension. This allows zipped files to be sent with .exe files and encrypted zip’s.

Step by Step Guide:

Creating the .JMU file

  1. Open My Computer or Windows Explorer, and navigate to the necessary file(s)
  2. Highlight the file(s) to be compressed. To select multiple files, hold down CTRL whilst selecting
  3. Right click one of the files, and select Send to >  Compressed (zipped) folder
  4. A .ZIP file will be created containing the selected files
  5. Replace the .ZIP file extension with .JMU

The file is attached to the email in the normal way - it is advisable to inform the recipient that the attachment should be renamed back to .ZIP and needs uncompressing.

Opening a .JMU file

  1. Save the attachment to a suitable location
  2. Change the file extension back to .ZIP
  3. Right click on the file, and select Extract All...
  4. The Extraction Wizard will open - follow the on screen prompts to extract the files to your PC.

Page last modified 13 January 2015.

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