How to Send Large Attachments via Email

A Google Script to use SaneBox alongside to manage email newsletters

EmailYou want to send a large file to a colleague or an external source – so how do you do this at the moment?Do you fire up Microsoft Outlook (or your choice of e-mail client), hit “New Message”, type in the recipients name, attach that 2mb Excel file and then click Send?Works right? Well – most of the time anyway… And anyway, it wasn’t an important file so it doesn’t really matter if it arrives eh?

Hold on? It *was* important?! The intended Recipient has been in touch and asked you when that file you were supposed to be sending is going to arrive! You get in touch with your IT Department or E-Mail provider and say “I sent this file, but it’s never arrived – where is it?”

They say “We don’t know” – and they’d be right – here’s why.

Email wasn’t built for large attachments

E-Mail was built way back in the mists of time with the intention of sending messages comprising entirely of text. This was before Excel files, pictures of Britney Spears or funny videos of pet Cats falling off chairs.

“But I have sent attachments before and they’ve arrived!” you add.

So they did. What happens when you attach a Word file, an Excel spreadsheet or any type of attachment to an e-mail is this. Your e-mail software converts it to plain text (Read more about MIME for the geeky explanation) and when your intended recipient receives that e-mail, his or her software converts that text back into the the attachment you sent. They open it. All is well. Most of the time, anyway.

Why don’t large attachments work?

Why shouldn’t that attachment get through ok? For starters, if you send the wrong type of file via e-mail it will get blocked by the recipients ISP, e-mail provider, or even company e-mail server as a potential virus. What’s the wrong type of file? Well that depends from system to system – some systems block JPG images, others even block Excel spreadsheets – it’s pretty much pot luck, you can’t tell until you’ve tried sending that file.

So let’s presume the type of attachment you want to send is allowed. You send the e-mail, but it arrives hours and hours later. Why? Well, if it’s a large file it may have been intentionally delayed. You see, not every e-mail recipient has an expensive speedy Internet connection ready to download tons of information. Some systems are slow, and the system administrators therefore have to make a choice between allowing your large attachment through via e-mail and delaying dozens or even hundreds of other e-mails, or allowing that majority of tiny e-mails to arrive quickly and postpone gathering your e-mail until overnight when things are a lot quieter.

Other ISP’s or e-mail providers simply block large attachments altogether. Depending on your provider, you may find the largest attachment you can send it 2mb, 3mb, 5mb or 10mb. They do this for the exact same reason we’ve just discussed – they want to allow that other 95% of e-mail traffic to arrive quickly and unimpeded by your mammoth e-mail.

Finally, you’ve chosen the right type of attachment, your ISP allows it, it’s not been blocked by any Virus or Spam filters and it therefore arrives – but your intended recipient tries to open it and Windows tells them the file is corrupted, Outlook steps in and says “That attachment might be dangerous, I’m not letting you open it”, or worse, your recipient tries to read his e-mails but everything has mysteriously ground to a halt on “Send/Receive”. They can’t click anything – Outlook has crashed! That huge video of the new-born Ducklings riding on a Skateboard you’ve sent them means they can’t use their e-mail at all. Thanks a lot buddy!

Recipient complains to you that your file is bad/corrupted/too big, you complain to your IT department, they hold their head in their hands and weep.

If you’ve not already got the gist of what I’m driving at here – it’s this…

Sending large attachments via e-mail is a bad idea.

Alternatives to sending large attachments

So what are the alternatives? Well you could burn that file to CD or DVD, pop it in the post and hope the Royal Mail delivers it. But they may be on strike, or worse, they may not be on strike and still not bother to deliver your package until 2099 as it’s 1 penny short on the postage stamps you’ve attached.

Fear not – there are electronic alternatives that make sending a large attachment to a recipient painless and easy. What’s more, they’re free!

The first option is my preferred option. It’s a web-site called YouSendIt. Go visit it now! It’s free to use for basic services, although a paid-for version offers some features you might find useful. You fill out the form like a normal e-mail, add your attachment as normal, and then click send (as normal). Your intended recipient receives an e-mail, as normal, except it contains a link to download the attachment you’ve sent instead of the actual attachment. Your recipient clicks said link, they download the file – voila! No fuss, no muss. Because the e-mail you’ve sent is plain text, it arrives instantly and because the recipient is downloading the file from the Internet directly as opposed to the file being transferred through a dozen different systems before it hits their e-mail server – they aren’t impeded by as many potential filters blocking the attachment or speed of download.

If you use Microsoft Outlook you can even install a handy free plug-in from YouSendIt that means you simply write your e-mail as normal, attach the file as normal, and click send as normal. YouSendIt then strips the attachment out, uploads it as you would via the web-site, and the intended recipient receives the original e-mail with the link to download the attachment – and all of this is done for you automatically without any change in your normal procedures!

There are other options for sending large files to someone, but none as simple as YouSendIt. If you’re really interested, go and take a look for more information on FTP (File Transfer Protocol), File Splitters (such as GSplit) or even Windows Live Meshwhich I’ve talked about before. All are free. I’d still pick YouSendIt over these options every time though.

Email Tips

Finally, a couple of other tips for sending attachments via e-mail.

If you’re sending the attachment to an internal colleague – why bother attaching the file at all? Simply send an e-mail containing a link to the location of the file on the shared network drive. If you’re both working on the same file then it means one less revision of that file floating around too!

If you’re sending a picture to someone via e-mail – why bother? Upload it to any of the photo sharing sites such as Flickr or PhotoBucket – and then send them a link to it’s new home on the web!

Same goes for videos. Don’t ever EVER send a video as an attachment! Upload them to YouTube and send the link via e-mail.

Resizing Images before sending via email

Finally, if you positively have to send a picture via e-mail – make sure you’ve resized it first. Go download Microsoft Image Resizer, install it, right click on the picture and click “Resize”. Your 2mb picture of Jess the Cat wrestling with a ball of wool will suddenly be reduced to a few KB, without any noticeable loss of quality. In fact, go download this free software now and use it to resize all those images stored on your Hard Drive or Shared Network Drive – I guarantee you’ll save around 75% of your disk space instantly. Neat huh?


So hopefully the above will help change your mind the next time you go to send that huge file via e-mail! If you decide to send me a large file via e-mail, expect me to reply with a link to this blog post!

Feel free to get in touch if you have any queries, or leave a comment – I’ll happily help you argue your case with any IT Department who disagrees with the above. šŸ™‚


photo credit: JASElabs via photopin cc


  • Richard Tubb2022-05-10 09:46:28

    Thanks for sharing, Kira!

  • kira2022-05-10 00:44:22

    I use fast and easy to use.

  • Richard Tubb2020-03-24 15:22:29

    Great tip, Pablo! Thanks for sharing!

  • Pablo2020-03-24 13:11:42

    One possible way to send large attachments is either to compress or reduce their size in any way, and the second is to upload them to the cloud by for example using OneDrive.... Attach2Cloud handles both ways in one single operation. For example the user can take a 200 MB (or even several GBs or even TBs) file from the local computer, drag this file and drop into an email... the file with a link will be instantly attached (in 1 second), when the user clicks on send, the file starts being transmitted to OneDrive in the background without any other further user needed action. Even more, the user can keep sending and receiving email normally while that file is being trasmitted. After that, the recipients will receive the modern Outlook attachment (or if the recipient is not using Outlook, then a link will be shown). So as you see it's only one single drag operation. It also supports the file-insert dialog, paste, and all possible ways of adding an attachment. Transparency and almost zero learning curve.

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