Hello,

I am currently evaluating SmarterMail with the Free license before moving forward with a purchase.

As part of the testing, I am developing an API integration for sending and receiving mail. Receiving works without issues, but I am running into a problem when sending mail using the SendMessage API.

Environment: ASP.NET C#

The problem is that regardless of which parameters I include in the request, the API always responds with:

var mailData = new
{
    to = "\"test@receive.com\" <test@receive.com>;",
    ownerEmailAddress = "send@test.com",
    from = "send@test.com",
    subject = "test",
    messageHTML = "test"
};

I have checked the community forum, but I have not been able to find a post that addresses this specific error.

Could you please advise what might be causing this?

• Is there an issue with the request payload format?

• Or is there a domain/mailbox configuration setting in SmarterMail that I need to adjust?

The API documentation does not provide enough information for me to determine the cause. Any guidance or suggestions would be greatly appreciated.

Thank you.