Mailchimp gets brutally expensive at the higher tiers, especially if you have a large list but only send 1 or 2 newsletters a month. We switched to sendgrid fo

Mailchimp gets brutally expensive at the higher tiers, especially if you have a large list but only send 1 or 2 newsletters a month. We switched to sendgrid for our newsletters even though their interface is not as nice. Their pay-per-delivery pricing fit our model much better than the pay-per-subscriber.