Visual Studio 2005 Version 8.0.50727.42
The task is to send an email to every recepient that is contained in a DataTable. After MailAddressCollection.Clear() MailAddressCollection.Count changes to zero, but the next message sent still contains the first MailAddress added to the MailAddressCollection. This can be seen only if there will be no new MailAddress added to the MailAddressCollection - see below if column "EmailCC" is empty.
Very strange. Any idea except from creating a new MailMessage for every recepient
private System.Net.Mail.MailMessage _Msg;
foreach (System.Data.DataRow row in table.Rows)
{
this._Msg.To.Clear();
this._Msg.CC.Clear();
...
this._Msg.To.Add (new MailAddress (row["Email"].ToString(), row["Name"], Encoding.Default));
if (!string.IsNullOrEmpty (row["EmailCC"].ToString ()))
{
this._Msg.CC.Add (new MailAddress (row["EmailCC"].ToString (), row["Name"], Encoding.Default));
}
...
smtp.Send (this._Msg)
}
System.Net.Mail: Method Clear() of MailAddressCollection leaves 1 element unremoved
hron
emman101
Hmm, I just tried, but I can't reproduce the problem: no matter how many To/CC recipients are in the message, the .Clear method always works as expected, and when I subsequently add new recipients (To and/or CC, in any order), only those new addresses show up.
Do you have a small piece of code that's actually runnable and that demonstrates the problem I use System.Net.Mail.MailMessage and SmtpClient in various apps, and have never seen anything like this...
'//mdb
Dmitriy Vasyura
Ah, interesting... I see it's a bit of a Heisenbug too: if you single-step through the code in the debugger, and look at the Msg object prior to the smtp.Send call, everything will seem OK (Msg.CC.Count == 0 on the second iteration of the loop). On a normal run, though, even with a breakpoint on smtp.Send, the Msg.CC collection definitely contains an address. The erroneous CC is in the output message in both cases (!).
I'll look into this a bit further tomorrow, but this seems like a genuine framework bug. Moving the MailMessage object instantiation into the loop fixes the issue, but there may be a workaround that has less perfomance implications.
'//mdb
Marian Luparu
Darren.Sim
By chance I found a better workaround for this issue than to re-instantiate the MailMessage with all its implications. Just adding the following pairs will do the "real clear":
MailMessage.To.Clear();MailMessage.Headers.Remove("to");
MailMessage.CC.Clear();
MailMessage.Headers.Remove("cc");
MailMessage.Bcc.Clear();
MailMessage.Headers.Remove("bcc");
Cheers!
Flecki
Sure I have, here you are:
public void Send () { System.Net.Mail.MailMessage Msg = new System.Net.Mail.MailMessage (); Msg.From = new System.Net.Mail.MailAddress ("from@123.com"); for (int i = 0; i < 10; i++) { Msg.To.Clear (); Msg.CC.Clear (); Msg.Bcc.Clear (); Msg.To.Add (new System.Net.Mail.MailAddress ("mailto@" + i + ".com", "name " + i, Encoding.Default)); if ((i % 2) == 0) { Msg.CC.Add (new System.Net.Mail.MailAddress ("mailcc@" + i + ".com", "name " + i, Encoding.Default)); } if (Msg.To.Count > 0 || Msg.CC.Count > 0) { System.Net.Mail.SmtpClient smtp = new System.Net.Mail.SmtpClient (); smtp.DeliveryMethod = SmtpDeliveryMethod.SpecifiedPickupDirectory; smtp.PickupDirectoryLocation = @"C:\Temp"; smtp.Send (Msg); } } }Now with i==0 will result in a mail with one To- and one CC MailAddress in the message. But with i==1 only the To MailAddress should appear, right
First eml file produced:But this is not the case:
Second eml file produced - please also note only 1 line starting with x-receiver:
Any hints highly appreciated 8-)