What Is an Email Quota and What Does “Over Quota” Mean?

After I did a recovery on my computer, my email program has not worked properly as far as the inbox is concerned. I used to be able to get 700-800 or more emails in my inbox (if I went on vacation or didn’t check for a while) and after the recovery, once I reached about 80 emails it started bouncing my messages saying I was OVER QUOTA!!! How can that be? It is getting worse now. I can have only 40 messages in my inbox and it will start bouncing my messages, still saying I am OVER QUOTA! Soon, I won’t get ANY messages!

Believe it or not, being over quota has nothing to do with the inbox on your PC, or even what email program you’re using.

But it might have everything to do with how your email program is configured.


A quota is nothing more than a limit on how much disk space your email can take up.

The catch is, it’s not on your machine; it’s on your email service provider’s server.

It’s your email service provider that imposes a quota on how much of their disk space you’re allowed to use. That could be Hotmail, Yahoo, Gmail, or the email provided by your company, your ISP, or whomever else you’re using.

For example, in Gmail, I have this message at the bottom of the page:

10.33 GB (60%) of 17 GB used

That means I have a space quota of 17 gigabytes. Presumably, if I exceed that limit — if I accumulate more than 17 gigabytes of email — Gmail will start rejecting email sent to me.

Over quota

The big clue in your question is this: the email program on your computer does not “bounce” email — your email provider does.

When your account is over quota, two things may happen:

  • Your email provider will reject email sent to you, since you have no more of their disk space available to store it. Usually the provider will send a bounce message to the sender, saying the mail could not be delivered.
  • Your email provider may send you an email message to let you know you’re over quota.

In either case, the fact that you’re over quota is being detected by your mail server without your mail program even being involved.

The most common cause for being over quota? Going on vacation.

When you go on vacation, you don’t download email, so it accumulates on your email provider’s server. If, while you’re away, the email you receive exceeds the amount of space the email provider has set aside for you, you’re over quota.

The only real solutions are to:

  • Ask for a larger quota (meaning more space)
  • Check, download, or clean up your email from time to time while you’re away
  • Move to an email provider with a larger quota, or no quota at all

Now, it sounds like you may have a little more going on, since after getting back (and presumably downloading your email) you’re still running into trouble.

Email program settings and going over quota

When you set up your email account in a desktop email program, one of the configuration options you specify is what type of email server you’ve been provided.

Each can have ramifications on the amount of space that will be used at your email service provider.

IMAP and over quota

IMAP by definition leaves all the messages that you don’t delete on the email service provider’s servers, in addition to copying them to your email program. In this case, the act of downloading and viewing your email does not free up any space against your quota — only actually deleting messages will do that.

If you use IMAP, which is a common default these days, and are reaching your provider’s email quota, you have three options to resolve the issue:

  • Ask your email provider for a larger quota. This may or may not be available, and may or may not require payment.
  • Delete messages. This might be the most practical approach if you want to keep using IMAP. If there are messages you want to save, perhaps save them to disk before deleting them from your email program. Depending on your email program, this can be as simple as moving them to a local folder.
  • Switch to POP3. More on that next.

POP3 and over quota

When you download email from a POP3 server, it’s downloaded to your machine and normally removed from the mail server. Thus the act of downloading email to your email program automatically frees up space counting against your quota.

There is an obscure setting I occasionally see set when people don’t expect it: “Leave a copy of messages on the server”.

The location of the setting varies depending on the email program you’re using, but the effect is the same: rather than removing the messages from your mail server when you download, it leaves them there, and they continue to count against your quota.

In addition to asking for a larger quota, as above, your options here include:

  • Turn this off, and remember that your computer will have the only copy of messages once they’re downloaded, so make sure you’re backing up!
  • Set or shorten the length of time after which email is automatically deleted.
  • Make sure to check the checkbox to immediately delete emails on the server when you delete them on your computer.

The bottom line is that if you’re over quota, you need to change how you manage your email so less space is used on your email service provider’s servers.

The impact of mobile email

One of the reasons you might be seeing “over quota” messages a little more often of late is the rise of mobile email. In addition to reading and dealing with email on your computer, you might also be using a mobile device, such as a mobile phone.

The “problem”, so to speak, is keeping your phone and your desktop email program “in sync” so that your view of email on both devices is roughly the same. Emails marked as “read” on one are marked “read” on the other, emails deleted on one disappear from the other, and so on.

The most common solution is IMAP. As I mentioned above, using IMAP, the “master copy” of your email is left on the email provider’s server, and your desktop and mobile devices are simply views of that master copy, though they may download local copies just to make things faster. Of course, as we’ve seen, IMAP leaves all the email on the server, making it more likely to run into a quota issue.

The other common solution is to enable “Leave a copy of messages on the server” in POP3. Again, as we’ve seen, that also makes greater use of the storage at your email service provider, and can similarly cause quotas to be reached more quickly.

The solutions remain the same: get a larger quota from your email provider, or save less email.

Originally published as What Is an Email Quota and What Does “Over Quota” Mean? on Ask Leo!