[unisog] What Email Attachments Do You Block?

Mark Borrie mark at gandalf.otago.ac.nz
Tue Jul 24 06:57:42 GMT 2001

We do not block any types of attachments as we do not want to get into the 
debate on what are valid ones to block etc.

If the reason for blocking certain emails is due to viruses then I suggest 
scanning the email for viruses.

We currently scan most email on and off campus for viruses using inflex 
(http://www.inflex.co.za/) and sophos (http://www.sophos.com). Sophos is 
very good at detecting viruses, while inflex is a bit unstable in some 
situations. I believe Sophos is working on a sendmail module.

We use 2 linux servers as our mailhubs. One is a single processor 700 MHz 
system and the other is dual processor 850 MHZ (or there abouts). These 
hubs take a huge load off our actual servers and simple relay the mail onto 
the correct server. By some DNS and router configuration we can ensure that 
all mail to and from a particular server gets scanned. 

Yesterday we had over 75 000 mails through the hubs. I think that may have 
been a slower day.


> What types of email attachments, if any, do you block completely?
> What effects has it had on general communications and student 
> submissions of projects specifically?
> Do you do any virus scanning on your mail server/gateway?
> If you don't want to post this information on a public
> list, send them to me directly and I'll sanitize and
> summarize.
> thanks,
> -- 
> Gary Flynn
> Security Engineer - Technical Services
> James Madison University
> Please R.U.N.S.A.F.E.
> http://www.jmu.edu/computing/info-security/engineering/runsafe.shtml

Mark Borrie
Systems Support Specialist and IT Security Officer,
Information Technology Services, University of Otago,
Dunedin, N.Z.
Ph +64 3 479-8395, Fax +64 3 479-5080

For information on email virus hoaxes see

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