There is a 600 outgoing email hourly limit per domain. This limit is also applied towards Mailman. If you send over this amount in any hour, most of the e-mails will bounce back with an undeliverable error. If this occurs, it will then take some time for your account to be able to send again so we recommend waiting at least 1 hour after this issue occurs to begin sending email again.
Each connecting IP to the server has a limit of 30 POP3/IMAP checks per hour. If you go over this you're likely to get a wrong password error message or an error stating "login incorrect". If this occurs, please wait an hour and it will automatically unblock you. To prevent this from happening again, please make sure to disable auto checking on your mail client or at least set it to something higher such as once every 10 minutes.
Large mailing lists (above 500 emails) should be sent during off-peak hours to avoid high server loads. Off-peak hours qualify as weekdays from 6pm to 8am and all day Saturday and Sunday.
All lists created 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. Any unsolicited e-mail being sent will result in suspension or termination of the offending account. We take a zero tolerance stance against sending of unsolicited e-mail and other forms of spam.
No direct SMTP mailers are allowed. An example of this would be a Darkmailer or The Bat!. Any mail should be sent through the local mail server/MTA for further delivery by the server and not done directly by scripts.
You must throttle all large email lists. We recommend you throttle it to at the very least sending 1 email every 8 seconds. (meaning 450 emails within 1 hour, keeping you below the 600 outgoing email limit.) If the mailing list software you're using does not allow you to throttle you must switch to an application or script that will. We recommend PHPList, which can be found in your CPanel under Fantastico. If you do not throttle your mail, the server will attempt to send all the emails in 1 sec which will not be possible.