SMTP quota

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DreamHost Enforces Outbound Mail Limits/Quotas

In our effort to combat the ever increasing problem with Unsolicited Bulk E-mail (UBE), a.k.a. "SPAM", we reserve the right to limit the number of recipients per hour to which customers can send e-mail messages.

Q: How does this help?

A: The better we can limit the amount of spam originating from our systems (and spam forwarded through our systems), the less likely our servers are black/gray listed by other ISPs and e-mail services. This in turn allows us to provide more reliable service to our customers (you!).

If you receive an error message when trying to send mail which says "Policy Rejection- Quota Exceeded", that means that you have exceeded or attempted to exceed your mail sending limit for that particular account. Also, if you attempt to send messages and do not use the correct FROM address, the system gives you this error and does not send your messages.

Default Sending Limits/Quotas

SMTP Authentication (regular) e-mail accounts: 100 recipients per hour

  • Max recipients per message: same as sending limit
  • Max message size: 40MB (encoded)

SMTP Authentication (webmail) e-mail accounts: 100 recipients per hour

  • Max recipients per message: same as sending limit
  • Max message size: 10MB (PHP max upload limit) for SquirrelMail and RoundCube

FTP/shell accounts on shared web servers (sending using scripts via PHP/CGI, etc.): 200 recipients per hour

  • Max recipients per single message: 40
  • Max message size: 40MB (encoded)

FTP/shell accounts on VPS and dedicated servers (sending using scripts via PHP/CGI, etc.): unlimited recipients per hour

  • Max recipients per message: unlimited
  • Max message size: 40MB (encoded)

DreamHost "Announce Lists" (configured via our control panel): unlimited recipients per hour

  • Max recipients per message: unlimited
  • Max message size: 40MB (encoded)

Discussion Lists (created via our control panel): unlimited recipients per hour

  • Max recipients per message: unlimited
  • Max message size: 40MB (encoded); individual list may set a lower limit

Notice that these limits are based on the number of RECIPIENTS, not the number of messages! A single e-mail message with 5 recipients would count as 5 towards your sending limit.

All recipients in the TO, CC, and BCC fields are counted.

Examples

If you send...

  • a single message with 100 recipients (for SMTP accounts), you reach the maximum sending limit for that hour. After one hour, you can attempt to send more messages.
  • 5 messages with 5 recipient each during one hour, the system counts this as 25 recipients during that hour.
  • 100 messages with a single recipient each (for SMTP accounts), you reach the maximum sending limit for that hour.
  • messages to 50 recipients and then within that same hour tried to send another message with 55 recipients, the second message FAILS and your account is blocked because it exceeds your sending limit. You must wait for that hour to elapse (from the time you send the first message) before you can attempt to resend the message which could not be sent during the last hour.

Once you have reached your hourly sending limit, any message that you attempt to send that exceeds your sending limit causes your account to be blocked immediately. Those messages that exceeded, or attempted to exceed, your sending limit are NOT sent and fail with a "Policy Rejection- Quota Exceeded" error message. Those unsent messages typically remain in your e-mail client's "outbox" so that you can attempt to resend them later.

However, the mail servers AUTOMATICALLY unblock/reset your account one hour after the first message that was sent. There is no need to contact support when this happens.

If you attempt to send a message that exceeds the maximum number of recipients, it always blocks your account!

Accounts that are blocked repeatedly for attempting to exceed the sending limit are blocked permanently by the system. They are required to contact technical support for assistance in order to have their account unblocked. In your support request, please include your email username and email address.

Even though a message that has been successfully sent to a recipient and "bounces" back to you for various reasons, it still counts towards your sending limit. They are not deducted from your sending limit.

Announce Lists

If you need to routinely send e-mail to a large number of recipients, we strongly recommend that you set up an Announce List via our control panel specifically for that purpose. It makes dealing with large groups of subscribers very easy and you don't have to worry about sending limits/quotas! Our Announce List feature manages the opt-in confirmations for you which complies with our Anti-Spam policies.

If you wish to set up an Announce List via our control panel, go to (MAIL > ANNOUNCE LISTS).

See the DreamHost Announce List Wiki article for more information.

Viruses Spyware and Adware

Viruses, spyware, and adware can infect your computer and send e-mail to everyone in your e-mail clients address book! Or, they may just use your e-mail account to send out its spam messages. The sending limits help to curtail the amount of "damage" done by these terrible breaches. If you know that you have not exceeded your sending limits and receive the error "Policy Rejection- Quota Exceeded", then contact support. Give us the e-mail address/username that is being blocked and we can review the mail logs to determine what has happened. It could be that e-mails have been sent through your e-mail account without your knowledge. If that happens, you must run virus, spyware, and adware scans to clean up your computer.

Important Notes

  • If you have an account set as forward to any e-mail sent to an another address, those forwarded messages also count towards your sending limit.
  • If you have Keyword Filters on an account that is set to forward any e-mail to an another address, those forwarded messages also count towards your sending limit.
  • Auto-responder messages also count toward that account's hourly sending limit.
  • If you use Cron jobs to send e-mail, they count towards the shell account's hourly sending limit. Cron job completion/error notification e-mail count too!
  • Multiple websites hosted under the same FTP/shell account that send e-mail all count towards that FTP/shell account's sending limit!
  • Cron jobs and other scripts/CGI processes that use authenticated SMTP to send e-mail messages are restricted to the sending limit of the address that they use for authentication.
  • Email limits are per email address. This does not mean you can "spread" your bulk/mass email across several email addresses. If you need to send more than 1-2 emails every minute, then you should review the DreamHost anti-spam/bulkmail policy at http://www.dreamhost.com/spam.html.

Incoming Message Limitations

  • The sending limits do NOT apply to incoming messages. Just for completeness, here are two incoming message limitations:
    • Maximum message size is 40MB. Incoming messages over 40MB are bounced.
    • The amount of disk space you've allocated to your mailbox: if your mailbox fills up, it bounces incoming messages. You may not even be able to delete any messages because the server needs some free space in order to work. So, try to avoid allowing your mailboxes fill up. See the Email_Setup article for more information on setting the "Limit total disk usage" and "Email me daily" warning messages for your accounts.
  • We recommend allocating at least 100MB for each mailbox. With a 40MB message size limit, just a few large message can fill your inbox.
  • We recommend enabling the "Email me daily" warning messages for your accounts! This helps keep you out of trouble.
  • If you have the "Save removed messages" option enabled (which is the default option), those saved messages can eat up your disk space without you ever seeing them! Make sure that you've subscribed to the "old-messages" folder (or whatever you've configured it to be) so you know what's in there.
  • If you have configured one of your FTP/shell accounts as the mailbox for your e-mail address and it's also used to store your web hosting directories, the disk limit/quota applies to BOTH. Make sure that you take that into account when setting a disk limit. It's easy to shoot yourself in the foot by setting a limit that is too low. In most cases, it's probably best not to set a disk limit for these types of accounts.

Log Output

If we send you the output from our logs for your verification, here's how to interpret them.

Example:

-------1------- ------2--------- ---------3--------- ---------4------------- -----------5------------- 
Jan  2 07:40:47 throttle=new(a), host=99.128.162.62, from=user@mydomain.com, to=family@somedomain.com, 
------6-------- ------7------- ---------8--------- ----------------9--------------
count=1/100(1), rcpt=1/100(1), threshold=0%|0%|0%, sasl_username=user@mydomain.com

The fields are as follows:

  1. Date and time
  2. Throttle status code (See details below)
  3. Host IP address of mail client (WebMail shows up as 127.0.0.1)
  4. "From" address
  5. "To" address (cab also be from CC or BCC field)
  6. Message count - number of messages during this period / period limit (messages can have multiple recipients)
  7. Recipient count - total during this period / period limit
  8. Threshold info (percentages) - the 3rd one is the only relevant one
  9. "sasl_username" - account used for SMTP authentication (WebMail does not show this field)

Ignore numbers or letters in parenthesis in the log output.

Throttle status codes and meanings-

  • new = Initial throttle start (first message sent beginning a new period)
  • clear = Throttle restarted (first message sent beginning a new period)
  • update = Update to throttle (current period in process)
  • abuse = Throttle exceeded. Account blocked until throttle period expires. No messages sent. See examples above.

Links

See these links for more details on our policies;