We are facing a difficult problem sending mail via Mandrill SMTP silently fails when mailFromName in the below code contains "æ", "ø" or "å". The mail is send perfectly well when we use another SMTP.
Mail.ReplyToList.Add(New MailAddress(mailFromAddress, mailFromName, System.Text.Encoding.UTF8))
We use the .NET smtpClient class.
Dim SmtpClient As New System.Net.Mail.SmtpClient
SmtpClient.Send(Mail)
SmtpClient.Dispose()
UPDATE
As suggested in comments, I agree this looks like an encoding problem but can't see what I can do about it on our side.
It seems to be only connected to the RepleyToList containing æ,ø and å and not Mail.To, which I define in similar fashion like this:
Dim mTo As New MailAddress(mailToAddress, mailToName, System.Text.Encoding.UTF8)
Mail.To.Add(mTo)
mailToName can contain æ, ø and å and is send perfectly okay.
Difficult to prove that something does not happen, but I am sure mails are not send and I am sure it is connected to the sendername in replyToList.
How I know?
I log the mails just before sending. Mails containing the characters in question are logged but never visible in https://mandrillapp.com/activity and never reach the recipient. I remove the æ, ø or å - all is visible in Mandrill Overview and all okay.
Wanna see my full code?
Here it is, note that sending mails which fails does not produce exceptions.
Public Sub sendMail(ByVal mailFromAddress As String, ByVal mailFromName As String, _
ByVal mailToAddress As String, ByVal mailToName As String, ByVal mailCcAddress As String, ByVal mailBCcAddress As String, _
ByVal mailPriority As Net.Mail.MailPriority, ByVal IsBodyHtml As Boolean, ByVal mailSubject As String, _
ByVal bodyPlain As String, ByVal bodyHTML As String)
Const maxtry As Integer = 3
Dim tries As Integer = 0
Dim failed As Boolean = False
' mailFromName = mailFromName.Replace("æ", "ae")
Do
tries += 1
Try
failed = False
Dim Mail As New MailMessage
If mailFromAddress <> String.Empty Then
'Mail.ReplyTo = New MailAddress(mailFromAddress, mailFromName, System.Text.Encoding.UTF8)
Mail.ReplyToList.Add(New MailAddress(mailFromAddress, mailFromName, System.Text.Encoding.UTF8))
Else
'Mail.ReplyTo = New MailAddress(Me.MailAddressFrom, Me.MailAddressDisplayName, System.Text.Encoding.UTF8)
Mail.ReplyToList.Add(New MailAddress(Me.MailAddressFrom, Me.MailAddressDisplayName, System.Text.Encoding.UTF8))
End If
Mail.From = New MailAddress(Me.MailAddressFrom, Me.MailAddressDisplayName, System.Text.Encoding.UTF8)
Mail.Sender = New MailAddress(Me.MailAddressFrom, Me.MailAddressDisplayName, System.Text.Encoding.UTF8)
If mailToAddress <> String.Empty Then
Dim mTo As New MailAddress(mailToAddress, mailToName, System.Text.Encoding.UTF8) 'UTF8
Mail.To.Add(mTo)
End If
If mailCcAddress <> String.Empty Then
Dim mCc As New MailAddress(mailCcAddress)
Mail.CC.Add(mCc)
End If
If mailBCcAddress <> String.Empty Then
Dim mBCc As New MailAddress(mailBCcAddress)
Mail.Bcc.Add(mBCc)
End If
Mail.Priority = mailPriority
Mail.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure
Mail.IsBodyHtml = IsBodyHtml
Mail.HeadersEncoding = Encoding.GetEncoding("utf-8")
Mail.Subject = mailSubject
Mail.SubjectEncoding = Encoding.GetEncoding("utf-8") ' = System.Text.Encoding.Default 'UTF8 'Default ' Test on all possible encodings
If IsBodyHtml Then
Mail.AlternateViews.Add(AlternateView.CreateAlternateViewFromString(bodyHTML, System.Text.Encoding.Default, "text/html"))
End If
Mail.BodyEncoding = Encoding.GetEncoding("utf-8")
Mail.Body = bodyPlain
' Add to log
addToMailLog(mailToAddress, mailCcAddress, mailSubject, bodyPlain)
' Send
Dim SmtpClient As New System.Net.Mail.SmtpClient
'SmtpClient.ServicePoint.MaxIdleTime = 1
SmtpClient.Send(Mail)
Me._status = EMailStatus.EOkay
SmtpClient.Dispose()
Catch ex As Exception
Dim debugInfo As New CDebug("sendMail", "Try: " & tries.ToString & ", UserId: " & Me.UserId, ex.ToString, Me.UserId, String.Empty)
Me._status = EMailStatus.EMailSendError
failed = True
End Try
Loop Until (failed = False Or tries >= maxtry)
End Sub
UPDATE II
I have now tracked the SMTP communication using WireShark. See screenshot which shows communication for a mail which was not delivered and does not show up in the Mandrill activity list - even though we get SMTP response OK and queued id.
I have three examples:
DELIVERED:
mailFromName = "xxx xxxxxxxxx xxxx - xxxxxxxxxx xxxxxxx xxxxxxxxx"
NOT DELIVERED:
mailFromName = "xxx xxxxxxxxx xxxx - xxxxxxxxxx xxxxxxx xxxxxxæxx"
DELIVERED:
mailFromName = "æxx xxxxxxxxx xxxx - xxxxxxxxxx xxxxxxx xxxxxxxxx"
