For send emails we need SMTP Server or Mail Server. Sometime outbound SMTP is restricted and sometime companies don’t want maintain mail servers. In such type of situations MailGun is good options.
With the help of MailGun developer just need a call APIs according to requirement and all process done by MailGun APIs.
MailGun support many popular programming languages including C#, Ruby, PHP, Python and Java.
Note: Current Version of API only support sending emails. Future version will support incoming emails, tracking and analytics.