There is a 400 outgoing email hourly limit per domain. This limit also applies toward Mailman. If you send over this amount in any hour, most of the emails will bounce back with an undeliverable error. If this occurs, it will then take a great deal of time for your account to be able to send email again. We recommend waiting at least 2 hour after this occurs to begin sending email again.
Many of our servers have a limit of 60 POP3/IMAP checks per hour per IP address. If you go over this limit then you are very likely to get a wrong password error message or an error stating “login incorrect”. If this occurs, please wait 2 hours and you will automatically be unblock. To prevent this from happening, please make sure to set up auto checking on your mail client to something higher than every 1 minute.
Any mailing list larger than 5,000 addresses will require a dedicated hosting solution. Note: Slitting a large list into smaller lists to get below this limit is prohibited.
There is also a limit to the number of Mailman mailing lists permitted. (NOTE: This does not apply to other mailing list programs such as PHPList. This only applies to Mailman.)
- Shared Hosting Package: 5 Mailman mailing lists
- Dedicated IP Hosting Package: 15 Mailman mailing lists
Mailing List Rules
1. Any time you are sending a message, regardless of how large your email list may be, you must throttle it. We recommend you throttle it to at least sending 1 email every 8 seconds. (Sending 1 every 9 seconds would send 400 emails within 1 hour, putting you at the maximum of 400 outgoing emails per hour limit.) If the mailing list software you’re using does not allow you to throttle your mailings, then you must switch to an application or script that will. We recommend PHPList, which can be found in your CPanel under Fantastico.
IMPORTANT: If you do not throttle your emailings and you try to send more than 400, the server will try to send all 500 in 1 second which is not possible on our shared servers. This will cause a very high load on the server and the entire server will be sluggish, potentially affecting your sites and service (and others), until this sending process is completed. It is our job to keep the server up and running without being sluggish or experiencing issues. Anyone who causes the server’s load to go high will be suspended and the process will be terminated. If you choose not to throttle, you will most likely be suspended for crashing the server.
2. Any mailing list over 900 email addresses is only allowed to be sent during off-peak times to prevent high server loads. Off peak times qualify as all day Saturday and Sunday, and 1AM – 8AM Eastern Standard Time, Monday through Friday.
3. The list must be a Double Opt-In list. This means a user has subscribed for a newsletter or other email marketing messages by explicitly requesting it and confirming the email address to be their own. Confirmation is usually done by responding to a notification/confirmation email sent to the email address the end user specified. The double opt-in method eliminates the chance of abuse where somebody submits someone else’s email address without their knowledge and against their will. You will not be permitted to mail any mailing list that you were given or purchased. In doing so, this will also be considered spamming and may result in termination of the offending account.
4. Any unsolicited email being sent will result in suspension or termination of the offending account. We have zero tolerance against the sending of unsolicited email and other forms of spam.
5. Any mailing list MUST comply with all guidelines set forth by the United States government. These guidelines can be found HERE.
6. No direct SMTP mailers are allowed. Any mail should be sent through the local mail server for further delivery by the server. No email should be sent directly by scripts.