I have a client with a need to send around 400 - 500 K emails per month. They are entirely legitimate opt-in emails to the customer base of their major online shop.
The email content is produced in house, and the sending of them is done by Nesox Email Marketer, which is now struggling with the volumes. Up until recently we have been relaying via the clients ISP, however this facilty has been withdrawn due to the volume.
We are now using the services of smtp.com, and are paying around $300 per month for 300,000 emails. However delivery of messages is slow, it might take a couple of days to send to a segment of around 40,000 people. Ideally we would like to load balance the sending via multiple smtp servers, but I cannot find any which will handle the volume.
Direct DNS delivery is not an option due to the amount of work involved in maintaining the reputation of the domain and IP address.
It seems the next step is a fully outsourced marketing solution, however we are talking mega money for this service and the cost cannot be justifed, also we lose some of the integration with the customer's on site data and the ability to segment the database for different campaigns.
What do people recommend for handling this volume of emails? Any feedback appreciated.