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November 2, 2009

Why It's a Bad Idea to Send Huge Files by Email

Gmail has increased the maximum attachment size to 25 MB in June, but some people want to send larger files. Daniel wrote a thoughtful comment that explains why it's a bad idea to send huge files by email:
People who demand large message size limits rarely understand the limitations of the email transmission.

Because of the MIME encoding used when sending binary attachments, your files expand 33% when sent via email. In other words, a 15MB attachment requires 20MB plus the message text, plus message headers.

When you carbon copy 20 of your friends & coworkers, a separate message is sent to each. 20MB x 20 = 400MB. That's half a freaking CD.

If 5 of those friends are on the same small company email server, downloading those messages saturates the entire bandwidth of their T1 data line for nearly 9 minutes. Because each message has separate headers, it isn't easily cached and gets completely downloaded by each recipient.

Compare this to uploading the same attachment to a web server, FTP server, file transmission service like YouSendIt, or video streaming site like YouTube. One copy is uploaded. The download is typically 8-bit so minimal expansion factor. The small business' network can cache the content, so it's only downloaded once then fetched locally from the web caching server.

Bottom line, sending a large attachment via email is relocating using the U.S. Postal Service as your moving company. It is painful, limited, and expensive.


  1. "It is painful, limited, and expensive."

    It's also easy.

    I agree with the premise of Daniel's comment but if I want to send a large file to one person, then email is the simplest way to send it.

  2. People should know how to bcc, how to cc, when to use email lists and when not to use email or to keep the freaking size of the mails low.
    Attachments are a hack to the protocol, but they don't seem to notice due to the efforts of gmail and others to make it look like a full featured product.
    But people just don't care.
    Email was good when the only people who used were educated and thoughtful enough to care. nowadays, not even developers know the protocol. Email is dead, it's too complicated, hacked and old.

  3. So why google hasn't yet released Gdrive?

  4. Seriously, I can't wait for Gdrive.

  5. I think that this could be solved by e-mail clients! If I want tweet picture - my client upload photo and get short url for my tweet. Why e-mail client can't upload file in the background and insert URL in the e-mail? Do you know any e-mail client that has this feature?

  6. So - to echo Martin Pelant - why doesn't Google still not offer a better service than YouSendIt, LiveSync or ftp?

  7. I think they wont release GDrive, as this will be taken care of with Google Wave.

  8. I hope they will release gdrive if not before, at latest with Chrome OS

  9. This post submitted to Reddit:

  10. a clean Google-style solution could be to automatically detect large attachments and replace them with a link to the files. The files would be hosted on Google-land and only available to the email recipients.

    This would be transparent to both the sender and the receiver.

    Isn't this very easy?

    It could be even implemented both ways, when sending/receiving from a address

    ciao -- Nando

  11. +1 to Nando1970's comment. Google could store the content on their servers and provide a link. It would save having to use file hosts which are full of dodgy ads! Maybe this will be an option when GDrive gets released. I guess the only issue is that instead of downloading the file with the mail, you'd have to be connected to the net to get at it in the future, so it should perhaps be optional.

  12. 2 thumbs up for Nandos idea. It would definitely be a very convenient solution for huge files.

  13. +1 to Nando1970. they could even have the option to just create a very long random signature for the attachment (like a google voice message link) that would not require a google account to download.

  14. It is expensive to Google, not me. I haven't pay any to use email.

  15. 5/5 stars, +1 for Nando1970

  16. Google doesnt implement a file managment system because the legal issues about copyright, g.e. you could send a movie or a song into a email. They neither, implement a detect size of file system because the files are embed into the mails and modify any part of it its ilegal

  17. This is the first time I've heard any Google representative make an excuse.

    This will not be the first time Google's cloud solutions will get hit with enterprise demands. We're counting on you.

  18. @Chris:

    What Google representative? This blog is not affiliated with Google and Daniel doesn't work at Google.

  19. Indeed, email is archaic. That doesn't mean that Google couldn't make it better.
    I've ALWAYS wondered why I couldn't attach a file to an email and have it available to many recipients as a download instead of a MIME encoded jumble of garbage.
    It even seems as if it would be quite simple to implement. All Google has to do is embed an FTP client into Gmail.

    Sending a pic or a song that's less than 2megs? Attach it as a mime, just like normal.
    Have something larger? Then select "store this attachment in my Gmail for multiple downloads" and automagically insert the link for the email.
    Encrypt it going both ways, make the link something you cannot post (to make it a public file) and Google wouldn't have any more responsibility for the content then a typical online backup solution does.
    Probably the trickiest thing is to make the link so it cannot be published. This could probably be done by automatically assigning rights for the file during the email sending process... (only the recipient gets added to the "allowed" list)

    This solution would make Google even better and would set them above he rest again.

  20. Sending large attachments consume so much space everywhere. Consider this, an employee sends a 50 MB report and makes sure his/her boss is copied, and the recipient boss is copied. Now, there are four people who has a copy of the report although only two of them really care about it. Just not that, the mail servers enroute may store a copy in it's cache, it's backed up so many times and the list goes on. No wonder, we are becoming more and more space hungry.

    We at have developed a solution similar to what Nando described - with a number of bells and whistles. Would like to add more bells and whistles as time progresses.

    Yes, I am part of sendeaZy team.

  21. Yahoo has cleverly integrated into their system. Google should do the same. Also, this blog post would have been great had it included a solution.

  22. I just use

  23. Right now Live Skydrive is the best way for emailing large attachments but once we have Gdrive, which will most likely be released with Chrome OS, if ever, we will have a much more integrated solution with gmail.

  24. por correo uno comparte cualquier correo sencillo y alguna que otra informacion. pero es bueno para mi que nose limiten ara nada como lo han venido haciendo, para mi la tecnologia no tiene limites y por ahora cuando quiero enviar un archivo de 25 mb a 100 uso megaupload o rapichare la verdad hay mas y si quiero cargar un achivo un poco mas grande como de 100 mb a 4Gb uso letitbit que es gratis bueno es cuestion de busca la mejor solucion y si gmail no quiere ampliar se usa otra paguina contal nadie es indispesable en el mundo sino el no lo hace, lo puede hacer otro ya que es una cometencia y al usuario hay que complacerlo porque es mas facil decirle al usuario que descargue o cargue archivo a tener que decirle reflexiones.
    hoy en dia la tecnologia nos acostumbro a que esto evoluciona cada min. cada vez salen y salen mejores versiones de programas
    es cuestion de donde uno se sienta comodo y facil de entender
    sin mas nada que agregar por ahora aporto mi opinion

  25. @ Jonnathan

    It would have been better if you would have written it in English.

  26. Nando1970's idea is great, but lots of employees only have a crippled access to the web (or no web access at all). So they *have* to send files by mail.

  27. Nice information. What a great post! I’ve enjoyed my time here!!!!
    Keep it up.

  28. facilitates this. Sending or Receiving large files made easy with sendeazy. File or a folder can be zipped automatically and sent to any mail-id just by a click. Just Drag and Drop the File or Folder or use Send to Facility in Sendeazy.

  29. Large files when they sent thru email leave a copy enroute to the destination in the servers. Thus lot of space is occupied. Thus sending large files using Email is a bad idea. But sendeazy provides a solution to this. Works on Nando idea. Sending large files or receiving large files is made easy with Lot more facilities like encrypted tranfer, Password protection etc., are keeping sendeazy ahead in file or folder transfer solutions.

  30. Hi,
    It's a Bad Idea to Send Huge Files by Email ...
    There might be a limitation on the size of the file !
    Your mail box get filled ....!
    Copy of the file is parked in different servers on it's way to Destination!
    I have tried sendeazy s/w from, Get out of all the above problems. Limited free regis. also available. Try it out...

  31. Yes,
    Why should we use emails for large files when there are some options coming up to transfer large fimes.
    I have used a service from site It can be one way to send the files.
    It is a private P2P application that runs on your computer and manages transfers of files within your network.

  32. Hi Nick,
    The above link is not working. It should be

  33. we've been using at the agency to send large files to clients... clients appreciate a nice delivery system of digital assets they pay a lot of money for. Simply sending it by email does not do our work justice.