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We all still need Email size limits

There are so many modern day ways to transfer large files, that it still saddens me that the only method anybody can conceive of using is by sending attachments in emails.  It does not surprise me when people continue to ask for larger message transfer sizes.  I work for a manufacturing company whose only resource to move information around has become email.  While FTP and other transfer methods have existed for years, without exposure to these technologies, the mainstream office worker only knows email.

heavy_emailThis week I found myself defending the restriction on message size limit against our organization itself.   When people stop trusting the restrictions I put in place, it tells me I need to pause enough to listen to what real problems might be happening.

The administrator who tells you that they don’t have any problems running higher or no limits in place, doesn’t have a grasp on his/her own resources or network.  While it is technically possible to open the limits up, there are reasons why it is just not done.

Why does there have to be a limit?

It is important to understand why we need to have limits in place. The first obvious one is that you make yourself more susceptible to Denial of Service attacks.  Now when I say “attacks”, people immediately jump to thinking about hackers and scary 8 year olds with hoodies on, trying to take down our network.  In reality you could inadvertently trigger a denial of service onto yourself, crippling your own network.

Large email sizes will directly impact network performance, as people transfer these larfe files around. If your office is running a T1 line for internet connectivity and you send or receive a 30MB file over that connection it doesn’t take much to see you could stop your network. If it was even possible to max out that T1 line at 1.544Mb, that would consume all of the bandwidth for 3 Minutes and 17.01 Seconds to make it happen.  You don’t actually have that full bandwidth available so it is easy to see how crippling this could be for smaller office.

A larger message size will also put an enormous strain on the client and the client antivirus software.  Most anti-virus programs scan messages within the mailbox and the large files may appear to lock up or stall the entire application.

I have a large pet peeve when people respond back with my requirements with “storage is cheap”.  You can certainly go buy another 5400 RPM hard drive able to store a terabyte of information for cheap.  Now multiply the number of people on a corporate network, expect to buy some enterprise level storage increases on you SAN network, and you will start to think differently.

What is a good limit?

Certainly necessity is the first rule.  If you NEED a larger limit, then everything else must adapt to keep up with what you need.  If you live and die by Microsoft best practices, you start with 10MB as the default setting on any Exchange mailbox.


Depending on the size of your organization, you will need to be proactive in determining how much of an impact increasing email size limits will have on your network, your clients, your servers and your storage.

What are my alternatives?

Most people in the organization don’t need to have this large limit in place.  Consider setting up a small group of people who might need a higher limit, and educate them on the dangers of sending and receiving the large files.

Make the files smaller.  I know that sounds simple, but it is.  The number one complaint from people getting blocked has to be powerpoint presentations gone to the extreme.  For some reason people aren’t very efficient at making powerpoint documents, using properly scaled images and going back later to compress the files size down.


There are hundreds of online storage services are available like putfile.com, filesavr.com or filefactory.com who allow you to transfer large files.  You will want to make sure you are not copying company sensitive information before using a service like this, but they can be very easy to use and setup.

If your company doesn’t have a secure channel for transferring files to customers, then push to make it happen.  The push for this doesn’t go to the IT department, but rather through management to identify the business need to make this happen.  While stretching the capabilities of your email system is not an option, it helps the company to identify why you are having problems in the first place.

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