Pushing the Envelope? Webmail & ISP File Size Limits

Pushing the Envelope? Webmail & ISP File Size Limits

Gregory Han
Feb 28, 2011
Click image above for full-size.

What's the biggest file size you've ever sent via email? It undoubtedly happens to us at one time or another. You're sending a batch of photos or a video attachment. You've even zipped the files for a smaller file size. Unfortunately, it's all for naught; your email bounces back! We've had this happen more times than we'd like to admit, so we thought we'd share some information about how much major email/ISP providers allow attached per email so you can avoid the bounce back blues.

We've recently migrated from Microsoft's latest Outlook for OS X over to Postbox 2, and we wholly endorse it as our favourite email client for design and utility (just in case you're wondering, not a paid endorsement…we paid for the app after our demo period expired). The company happens to also put out an interesting blog focused upon email productivity, of course, filled with useful tidbits of information like this list that inspired the infographic above:

"Like most policies of large communications services providers, e-mail file size limits are difficult to find and interpret. Many ISPs change their rules depending on the level of subscriber service. We assembled the list below from online and phone help desks at major U.S. broadband providers. For a definitive number, you may have to contact your ISP's help desk."

ISP and email provider file attachment size limits:

  • AOL: 25 MB
  • AT&T: 25 MB*

  • Cable One: 10 MB
  • CenturyLink: 10 MB
  • Charter: 10 MB
Comcast: 15 MB
Cox: 10 MB
  • EarthLink: 10 MB*
Frontier: 3 MB

  • Gmail: 25 MB
  • Hotmail: 10MB

  • Qwest: 10 MB

  • Time Warner Cable/Road Runner: 20 MB
  • Verizon:  8 MB*

  • Bright House Networks/Road Runner: 20 MB

  • Windstream: 1 GB
  • Optimum Online/Cablevision: 20 MB
  • Yahoo! Mail: 25 MB


Of course you can get around file size limits by using services like Gigasize, YouSendIt or Dropbox, but sometimes it's just more convenient to drag and drop attachments with your email rather than producing and embedding download links, so it's useful to know how much is "too much" when it comes to sending file attachments.

(Infographic: Unplggd; based upon information sourced from Sherman Dickman of Postbox Inc; Photo: Flickr member Kevin Fitzlicensed for use under Creative Commons)

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