Do not use Mailgun. Their support is extraordinarily poor if you use it for something mission critical. We've had our grandfathered in account downgraded twice now resulting in outages, and their support took _days_ to respond.
They were bought out by Private Equity a while ago so it looks like they are in the stage where the company's value is being extracted.
They were bought out by Private Equity a while ago so it looks like they are in the stage where the company's value is being extracted.