Account limits

Limits on storage space

There are two main storage limits on every account: one for mail, the other for your file storage. The limit depends on your account plan; we list them all in our pricing table. You can see how much of each quota you are using at the bottom of the sidebar in the Mail and Files sections of our web interface (below your list of folders).

We will email you if you get close to your account limit. You should either upgrade your account or delete some of your existing data to make room (make sure you empty your trash to recover the space if you are deleting mail).

When quota limit is reached

If you go over your Mail quota, further mail sent to your account will be rejected with a temporary 4xx error. This instructs the sending server to try again later, so if you get your account back under quota quickly (either by upgrading your plan or deleting some existing data), no messages will be lost. If your account remains over quota for a week, we will change to returning 5xx permanent error messages. This means all messages sent to your account at this point will bounce, and be returned to the sender as undeliverable.

These restrictions are lifted as soon as your account goes back under quota.

Limits on send/receiving email

To protect our service against abuse, there are per-hour and per-day limits on the number and size of emails you can send and receive from your account, dependent on your service level.

These limits are very high and 99.9% of our users never get anywhere close to hitting them. If you find yourself regularly getting close, you should upgrade your account. If you are already at the top account level, contact our support team to discuss your needs.

The following daily limits apply to accounts:

All Trial accounts Lite & Basic Full & Standard Enhanced & Professional Premier & Enterprise
Number of messages sent/received 120/see below 1,600/800 4,000/4,000 8,000/8,000 20,000/80,000
Total size of messages sent/received 240 MB/see below 120 MB/120 MB 600 MB/600 MB 2,000 MB/2,000 MB 4,000 MB/4,000 MB

Please note, to prevent abuse, all trial accounts are limited to sending a maximum of 120 messages per day, however the receiving limit is the same as for a full account. The sending limit is lifted to the full account quota as soon as the account is paid for. Also, note that when you send an email to multiple recipients, your quota is updated once for each recipient.

In addition to the daily limits, there is an hourly limit for each of these quotas which is half the daily limit, and a 10-minute limit, which is half the hourly limit. We also have limits for the number of messages from a single sender, to stop an automated system accidentally flooding your account and stopping other email from being received, and for the number of times you can log in to your account in an hour, to stop buggy clients from flooding our system.

Legacy Guest accounts have the same limits as trial accounts, with a receiving limit of 320 emails per day. Legacy Member accounts have the same limits as Lite accounts.

Limit on attachments and message size

You may send any kind of attachment, as long as the resulting email is under 70 MB in size (due to encoding issues this usually means an attachment of 50 MB). Attachments with double file extensions (e.g. filename.doc.exe) are not allowed, as they are commonly used for virus transmission.

Limits on uploading/downloading files

To protect our service against abuse, there are per-hour and per-day limits on the number and total size of files uploaded or downloaded from your file storage, dependent on your service level.

The following daily limits apply to your file storage:

All Trial accounts Lite & Basic Full & Standard Enhanced & Professional Premier & Enterprise
Number of files uploaded or downloaded 1,600 8,000 40,000 80,000 160,000
Total size of files uploaded or downloaded 20 MB 20 MB 1,000 MB 2,000 MB 6,000 MB

In addition to the daily limits, there is an hourly limit for each of these quotas which is half the daily limit, and a 10-minute limit, which is half the hourly limit.

What happens when limits are reached

When an hourly or daily limit is reached, further attempts to send/receive emails or upload/download files (depending on the limit breached) will be blocked. For emails the block will display a temporary 4xx type response. This does not result in email being bounced, it is simply delayed: the sending server should try again later.

The rate tracking counter is activated on the first event received of its type (email or file), and reset an hour after the first event received.

Here's an example for a user uploading and downloading files with a 1000 MB hourly file transfer quota:

10:15AM
10 MB uploaded. Counter starts at 10:15. Counter = 10 MB.
10:20AM
20 MB uploaded. Counter = 30 MB.
10:30AM
500 MB downloaded. Counter = 530 MB.
10:50AM
500 MB uploaded. Counter = 1030M. You are allowed the download/upload event that sends you over the hourly limit, but none after that until the counter resets.
10:55AM
10 MB download attempt fails. Counter = 1030 MB, over the limit of 1000 MB.
11:15AM
Counter resets.
11:30AM
200 MB downloaded. Counter starts at 11:30. Counter = 200 MB.

Why is the size of a message larger than the attachment?

Email is an old standard from many, many years ago that originally started as purely text data. Over time, as people wanted to send attachments, they updated the standard to include them, but also tried to keep it backward compatible so older email systems wouldn't "break" the messages.

To do this, any attachment added to an email is usually encoded into a form called "base64". In this system, each group of 3 binary bytes is encoded into 4 ASCII characters. This means a couple of things:

Our IMAP server stores emails in their original form, so any emails with attachments will be about a third bigger than the actual size of the attachments when you download them. The sizes reported on the mailbox screen, and the totals reported on the resource usage screen are of the original email as it is stored in our server.