Bulk email SMTP - allow more emails per hour

This is what I use:

-Different hosting's plans locally that is prime, not cheap packages.
-They all limit email sending between 300 to 500 emails per hour - well in my country, South Africa that is the average per provider.

Problem:

I have different sites and plugins that need to send more than the limited emails per hour, for example:

a) Newsletters
b) NEW JOB alerts
c) FORUM's
d) Learnerships - hundreds of learners that need to be notified of urgent updates that might be once a week/month/year.

My daily/weekly/monthly may be far below the average usage, but the hourly might be a big problem. One JOB post, and I have 1000 people who wants to know about it.

Any software, solutions, suggestions....

Thanks in advance.

EZ