There is a 100 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 email again. It’s recommended to wait at least 1 hour after this issue occurs to begin sending email again.
Many of our servers have a limit of 30 POP3/IMAP checks per hour per each user’s connecting IP address. 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 or at least set it to something higher such as once every 10 minutes.
We monitor all sites for those that consistently meet or exceed hourly email limits. Purposefully running spam campaigns is the most common reason for reaching email limits, but your site may also be the target of a spam campaign. We reserve the right to turn off the PHP email function on your site if your email is being abused under any circumstance. Abuse can be intentional or unintentional, and we will notify you in either case.
Any unsolicited e-mail being sent will result in immediate suspension or termination of the offending account. To protect all of our customers, we have zero tolerance for anyone sending unsolicited email or other forms of spam from our network.
The CAN-SPAM Act of 2003 are national standards for sending commercial email. Any mailing list MUST comply with all guidelines set forth by the United States government. These can be found at The Bureau of Consumer Protection
You may contract a 3rd party email relay service rather than trying to mass email from our network.