Sending emails

AppHarbor doesn't offer SMTP support directly, and many IP addresses being used for Amazon EC2 is blocked in spam directories, it wouldn't be a good solution anyway.

For sending email, you can sign up with one of the following:

• Amazon Simple Email Service
• Mailgun (supported as an add-on)
• Postmark (used by AppHarbor)
• SendGrid (also an AppHarbor add-on)

In addition to these services, you can use Gmail or Google Apps for sending out a smaller number of emails, as well as external SMTP servers such as AuthSMTP.

If you use the Mailgun and Sendgrid add-ons, AppHarbor will automatically inject the relevant SMTP configuration. This lets you send emails like this:

var smtpClient = new SmtpClient();
smtpClient.Send(new MailMessage(...));