GMail API Emails Bouncing
gmail-api
Solution
This is crazy. This was the issue.
This line
msg.ReplyTo = New MailAddress(FromEmail, SenderName)
for whatever reasons (I guess when FromEmail and ReplyTo are same emails) leaves the RFC2822 `Reply-To` parameter blank. The parameter remains blank even when `msg.ReplyTo` is commented. Needless to say GMail API seems to have issues with Reply-To being left blank. Most definitely a programming bug.
So I had to do this hack in the final RFC2882 message.
inputTxt = Replace(inputTxt, "Reply-To:", "Reply-To: " & FromEmail)
It works now.
********* as pointed out in the comment below, you can use `MailMessage.ReplyToList.Add()` instead to solve this issue. So the issue here is that `ReplyTo` address is required in Gmail API (even though one might assume that `ReplyTo` should default to `From` email). **********
Problem
Using GMail API in .Net. Creating messaging using Net.Mail.MailMessage. Then using MimeKit to create MimeMessage (using this to send attachment + HTML message). Passing MimeMessage.ToString to Base64 encoder. No API error. Code runs through ok. I can see the message in the sent page in GMail. Mail looks perfect (and the send actually return message id). But then there is the following appended message to this mail in Gmail. ``` Bounce <nobody@gmail.com> An error occurred. Your message was not sent. ``` As usual, no other information from Google. How to fix this? ``` Dim msg = New Net.Mail.MailMessage msg.Subject = subject msg.To.Add(New MailAddress(ToEmail)) msg.From = New MailAddress(FromEmail, SenderName) msg.ReplyTo = New MailAddress(FromEmail, SenderName) msg.Body = bodyText msg.IsBodyHtml = True If Not String.IsNullOrWhiteSpace(fileAttachment) Then If System.IO.File.Exists(fileAttachment) Then Dim Attachment As New Net.Mail.Attachment(fileAttachment, "application/pdf") msg.Attachments.Add(Attachment) End If End If Dim message As MimeMessage = MimeMessage.CreateFromMailMessage(msg) Dim newMsg = New Google.Apis.Gmail.v1.Data.Message() newMsg.Raw = Base64UrlEncode(message.ToString) GmailService.Users.Messages.Send(newMsg, "me").Execute() Private Function Base64UrlEncode(ByVal input As String) As String Dim inputBytes = System.Text.Encoding.UTF8.GetBytes(input) 'Special "url-safe" base64 encode. Return Convert.ToBase64String(inputBytes).Replace("+", "-").Replace("/", "_").Replace("=", "") End Function ``` This is the return message. As you can see everything looks ok. Working with Google APIs is the most frustrating thing. ``` 200 OK - Hide headers - cache-control: no-cache, no-store, max-age=0, must-revalidate content-encoding: gzip content-length: 85 content-type: application/json; charset=UTF-8 date: Sat, 24 Jan 2015 05:57:21 GMT etag: "96Z6JVARoyR8skov3RseF4DCFpA/mFWFskkdSFxyjIhRJHJuhDCBvfY" expires: Fri, 01 Jan 1990 00:00:00 GMT pragma: no-cache server: GSE vary: Origin, X-Origin { "id": "14b1a841e4fff910", "threadId": "14b1a841e4fff910", "labelIds": [ "SENT" ] } ```