Overview
This article explains DreamHost's SMTP quota limitations and how to avoid hitting them when sending emails.
SMTP quota limits are set for all DreamHost email addresses and cannot be adjusted.
Limitations by sending method
The limits below are set for each individual email address and are based on the number of RECIPIENTS, not the number of messages. For example:
- A single email message with 5 recipients would count as 5 towards your sending limit since all recipients in the TO, CC, and BCC fields are counted.
- Also, if a message that has been successfully sent to a recipient bounces back to you, it still counts towards your sending limit.
| Sending method | Recipient per hour | Max recipient per message | Max message size |
|---|---|---|---|
| SMTP authentication in an email client | 100 | 100 | 40MB (encoded) |
| SMTP authentication in Webmail | 100 | 100 | 30MB |
| SMTP authentication in a web form | 100 | 100 | 40MB (encoded) |
| FTP & Shell users on shared servers. Sending using PHP/CGI scripts. | 200 (per server) | 40 | 40MB (encoded) |
| FTP & Shell users on VPS or Dedicated servers. Sending using PHP/CGI scripts. | Unlimited | Unlimited | 40MB (encoded) |
| Announcement Lists | Unlimited | Unlimited | 40MB (encoded) |
| Discussion Lists | Unlimited | Unlimited |
40MB (encoded) |
Examples of how the limits are implemented
The following examples explain how these limits are calculated and the outcome of hitting them.
| How the message is sent | Message and Recipients | Outcome |
|---|---|---|
| SMTP |
|
|
| SMTP |
|
|
| SMTP |
|
|
| SMTP |
|
|
Consequences of hitting the limit
Once you have reached your hourly sending limit:
- Any additional messages you attempt to send cause your account to be blocked immediately.
- Those additional messages are NOT sent and fail with a "Policy Rejection- Quota Exceeded" error message.
- Those unsent messages typically remain in your email client's "outbox" so that you can attempt to resend them later.
How long does the block last?
If you are blocked for exceeding quota, the block remains in place until at least one hour has passed, during which time there have been no further attempts to send mail from the account.
Accounts that are blocked repeatedly for attempting to exceed the sending limit are blocked permanently by the system. If this happens to your account, you must contact support to request your account unblocked. In your support request, make sure to include your email username and email address.
How to avoid hitting the limit
The following are different ways to avoid hitting these limits.
Email clients
Some email clients try to send anything in the "outbox" at regular intervals. To have the quota lifted as soon as possible, make sure to remove any message from the outbox and wait at least an hour before attempting to send again.
Web forms
DreamHost strongly recommends that users on shared servers send mail via SMTP, such as with PHPMailer or WordPress' WP Mail SMTP plugin.
Multiple websites hosted under the same FTP/Shell account that send emails all count towards that FTP/Shell account's sending limit.
Forwards and Autoresponders
If you have an account set as a forward to any email sent to another address, those forwarded messages also count towards your sending limit.
If you have custom filters configured to forward any email to another address, those forwarded messages also count toward your sending limit.
Auto-responder messages also count toward the hourly sending limit.
Cron jobs
If you use a Cron Job to send emails, they count towards the shell account's hourly sending limit. Cron job completion/error notification emails also count.
Cron jobs and other script processes that use authenticated SMTP to send email messages are restricted to the sending limit of the address that they use for authentication.
Incoming message limitations
The sending limits mentioned above do NOT apply to incoming messages. However, here are two incoming message limitations to be aware of:
- Maximum message size — This is set to 40MB. Incoming messages over 40MB are bounced.
- Mailbox disk space — 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 to fill up. See the Disk Usage Warning article for more information on setting the "Limit total disk usage".