If you are using smtp.hostwiz.co.uk the following sending limitations have been put in place to prevent any blacklisting of our mail servers, we have tightened up the operation of reseller and shared hosting SMTP. These cannot be changed.

200 Messages Per Hour

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)

Maximum Rrecipients is 25

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 our customers.