Emailing an attachment in C# through Office 365

Scenario: You want to send an email with attachment in C#, using an Office 365 account.

Solution:

SmtpClient client = new SmtpClient("smtp.outlook.office365.com");

client.Port = 587;

client.EnableSsl = true;

client.UseDefaultCredentials = false;

System.Net.NetworkCredential cred = new System.Net.NetworkCredential("user@callerip.ca", "passwwrd");

client.Credentials = cred;

                

MailAddress from = new MailAddress("user@contoso", "Caller IP");

MailAddress toEmail = new MailAddress("toaddress@email.com");

MailMessage mm = new MailMessage(from, toEmail);

mm.Subject = "Your subject";

mm.Body = "Message in email body.";

Attachment a = new Attachment(filename);

mm.Attachments.Add(a);

mm.BodyEncoding = UTF8Encoding.UTF8;

mm.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;

client.Send(mm);