Arrowmail - Email Services for today's Business

Also On This Page


How to Send Very Large File Attachments

If you're really lucky you might be able to send a 20 megabyte file as an email attachment and have it arrive in the recipient's Inbox.
However, for any attachment over 5mb, you can't be sure it will make it.

We can't do anything about this!
If we turned the attachment size limit on our servers up to, say 50mb, such large attachments would certainly be refused when we tried to send them on to the recipient's mail-server.

Using your On-Line Storage Space for Distributing Files

We've come up with a convenient alternative method to email attachments for getting files to people across the Internet.
Every Exchange Mailbox account comes with on-line storage space for files which can be accessed as a Web Folder, a mapped drive or using an FTP client.
If you drag-and-drop a file to your Web Folder or mapped drive, it's uploaded and stored in your storage areas on our server.
You need to supply a username and password to access these files so, although it's a very useful place to store your own current, and frequently-used, files that you want to you to access from anywhere or share with colleagues, you don't want to be handing out your password to people outside your company to enable them to get a copy of a file in your
on-line storage.

Here's Our Solution
In everyone's on-line storage location we have created a special sub-folder called Public.
This folder allows anonymous, read-only access so that anyone can download a file from there without having to supply a password, but cannot change or delete any files, upload new files, or see what other files are stored in your Public folder.
Therefore, instead of attaching the large file you want to send to someone to an email, you copy it to this Public folder and then send an email containing a link to this file.
For example:
If the file you've copied to the Public folder is called Brochure.pdf, the link you send will be:-

When the recipient clicks on the link in your email, the PDF file will open in their browser where they can chose to print it or save it to their hard drive.

OK, that link looks a bit complicated, but the part before Brochure.pdf is always the same.
If you take up the option to host your company or personal website from your on-line storage, we'll move the Public folder to be under your website folder.
The link to the file then becomes more straightforward:-

Remember that it's only you who has to type the link correctly - the recipient only has to click on it.

What if the recipient back-spaces the link so it reads:-


They get this:-

Browsing the Public folder isn't allowed. A visitor has to know the name of the file they want to download  

The recipient, or any other anonymous visitor, cannot therefore just view a list of files in your Public folder and download anything that looks interesting.
They need to know the name of a file stored in your Public folder in order to download it.

If they backspace the link further, to your top level Web Folder they'll get a logon prompt.

"Security through obscurity is no security"
Meaning: you shouldn't rely on files in the Public folder not being accessed by people you don't want to access them, just because they don't know the file's name.

It's therefore a good idea to delete any confidential files from the Public folder when you're sure the intended recipients have downloaded them.
The WebStats emails we send you, if we host your website, list which files have been downloaded.

This Method Doesn't Seem as Easy as Sending a File as an Email Attachment

That's because you're used to one method and not the other.
Is a new way of doing things worth the small amount of effort to learn, if it means you can get files to people more reliably and send much larger files?
Only you have to learn about uploading files with FTP as the people you're sending the files to will already know how to click on a link to download a file.
Using this method, the size of file you can send is now only limited by the amount of on-line storage you have, so files of several 100mbytes should normally be OK.
If you have the storage space available, it wouldn't be unreasonable to send someone a 500mb file this way, although the file upload and download processes might take many hours.

The fastest ADSL that's currently available gives 4mbps DOWN, 800kps UP.
(This is the 8 megabit ADSL Max connection where 4mbps download speed is what can be achieved in practice.)
Over an ADSL Max connection, a 350mb file will take a minimum of 73 minutes to upload, 15 minutes to download.
These times ignore "contention" where 20 or 50 other broadband connections share your bandwidth but, even with contention, this is still the most convenient way to transfer large files.

Replacing file attachments with links has several other advantages:-

If you're sending the file to multiple recipients, you save a lot of Internet bandwidth uploading the file once and then sending a lot of very small emails.

Your Sent Items folder doesn't contain a copy of the attached file which is usually a waste of your mailbox storage space.

The recipient can download the file when it's convenient for them.
They may resent having to download the file attachment in order to read the email text if they're on a slow Internet connection, such as when using a mobile device.

File types, such as EXEs, that are blocked as security threats by most emails systems, can still be sent this way.

If you find an error with the file your sending or it goes out-of-date, you can update the copy in your on-line storage (keeping the filename the same) hopefully before the recipient has got round to downloading it.

If you have a file that you regularly send to lots of people, like a brochure, then, if the file's already on-line, the process is even easier and you can also include a link to the file on your website.

You can, of course, continue to send smaller files as email attachments.

You can use Standard FTP or Secure FTP to Access On-Line Storage
If you Prefer

The process of getting files you want to send to others, into your Public folder needs to be easy.
FTP and Secure FTP  can be used to access your on-line storage location with, of course, the appropriate access permissions based on usernames and passwords so use whichever you feel most comfortable with.
My favourite is Secure FTP.
To use FTP, the hostname is, supply your normal username and password and you'll be connected to the root level of your on-line storage area.
FTP is a bit too technical for many people, but if you're familiar with it and like it's simplicity, then go for it.
If you want to use your on-line storage space for off-site backups, then some backup up programs don't understand Web Folders but can use FTP to perform backups.
There's more on using FTP to access your on-line storage here.

^ Top of Page ^

Feedback Form

Type your message below:-

Anonymous feedback is fine. If you'd like a reply then we'll need an email address to send it to.
We'll only use it to reply to your feedback, nothing else!


Email Address:

We sometimes like to publish visitor feedback, but only if you give us your permission:-

Choose a Screen Name for Published Comments:


If you prefer, you can, instead, email your comments to

^ Top of Page ^


© 2021 Arrowmail Ltd, a UK-registered company, number 4079706, registered VAT Number GB 895 0987 60
We welcome any comments about this website, good or bad. Send them to