The size of the largest allowable email depends on your membership level. For details see the pricing table . These are the sizes of attachments you are allowed. Due to the way that emails are encoded, an email with 10M of attachments could use 14-15M of quota - see Bandwidth Usage .
- Hourly limits
When an hourly limit is reached, further attempts to send/receive emails (for email limits) or upload/download files (for file limits) will be blocked. For emails the block will be a temporary 4xx type response, so the other side should try again later.
The rate tracking counter is activated on the first event received of it's type (email or file), and reset an hour after the first event received.
As an example, if the hourly bandwidth limit is 1000MB, then the following would occur:
- 10:15 - 10M used (counter starts at 10:15, counter = 10M)
- 10:20 - 20M used (counter = 30M)
- 10:30 - 500M used (counter = 530M)
- 10:50 - 500M used (counter = 1030M, you're allowed the download/upload event that sends you over the hourly limit, but none after that until the counter resets)
- 10:55 - 10M use attempt fails (counter = 1030M, over 1000M)
- 11:15 - (counter started at 10:15, cleared at 11:15)
- 11:30 - 200M used (counter starts at 11:30, counter = 200M)
- 11:35 - 100M used (counter = 300M)
- 11:45 - 900M used (counter = 1200M, again event that sends you over the limit is allowed)
- 11:50 - 100M use attempt fails (counter = 1220M, over 1000M)
- 12:30 - (counter started at 11:30, cleared at 12:30)
- Monthly limits
When you reach 75% of your monthly bandwidth quota, you'll be sent a warning email (both to your FastMail account and your existing/backup email address). You should probably upgrade your account, or purchase additional bandwidth at this point. If you reach 100% of your monthly bandwidth quota (including excess bandwidth you've bought), you'll have sending/receiving of email or uploading/downloading of files (depending which quota you've reached) disabled for your account.