Google Groups message limits
As a security measure, all Google Apps groups place limits on message activity. These limits restrict the number of messages sent per day, the size of files sent, the number of recipients per message, and more. After reaching one of these limits, you are temporarily prevented from the activity whose limit you reached. The restriction typically lasts for one hour, but can last as long as 24 hours.
The following limits apply for Google Apps for Business or Education editions. Limits for Google Apps for Business trial users are lower than those in the table below. The value of these limits may change without notice in order to protect Google's infrastructure.
|Total recipients per group||Maximum number of recipients for group messages||6,200,000 per hour|
|Total external recipients per group||Maximum number of external recipients* for group messages||5,000 per day|
|Total external recipients per domain||Maximum number of external recipients* for all groups in a domain||10,000 per day|
|Total inbound emails per group||Maximum number of email messages the Google Groups server accepts per group**||300 per 5 minutes|
|Total message size||Maximum total gigabytes for all group messages||244 GB per hour|
|Total messages per sender to a specific group||Maximum number of messages a sender can send to a specific group||1800 per hour|
* External recipients are recipients outside of your domain. For customer accounts with multiple domains, recipients in all associated domains count as internal recipients. The limit on external recipients increases with the size of the Google Apps account; a customer with 20,000 users has a limit larger than 5,000 per day
** If archiving is enabled for the group there is an additional limit: the maximum number of messages received per second by the group is 1 message per second.