Yobunny > Astarte Web Design > Support > Email bulk mailing limits...
To prevent any blacklisting of our mail servers, the following applies to our shared hosting SMTP email service.
Customers may now only send up to 200 messages per hour through our SMTP servers. Anyone attempting to exceed this limit will receive the message:
451 Sending rate limit has been exceeded. Try again later. (#4.3.0)
In addition, anyone attempting to send to more than 25 recipients in a single message will incur a delay of 10 seconds per SMTP transaction to each recipient.
This has been implemented in order to provide a smoother more reliable service for all of our customers.