Strange error in sending the mail through C# WinForm

Question

i have this code for sending mail through C# WinForm.

i have this reference:

Microsoft.Office.Interop.Outlook (version 11.0)

my code:

string sampleSource = System.Windows.Forms.Application.StartupPath + @"\TEST.txt"; 
string sampleDisplayName = "Test";
Microsoft.Office.Interop.Outlook.Application sampleApp = new Microsoft.Office.Interop.Outlook.Application();
Microsoft.Office.Interop.Outlook.MailItem sampleMessage = (Microsoft.Office.Interop.Outlook.MailItem)sampleApp.CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olMailItem);
Microsoft.Office.Interop.Outlook.Recipient sampleRecipient = (Microsoft.Office.Interop.Outlook.Recipient)sampleMessage.Recipients.Add(sampleSource);
sampleRecipient.Resolve();
sampleMessage.Subject = "Test sub"
sampleMessage.BodyFormat = Microsoft.Office.Interop.Outlook.OlBodyFormat.olFormatHTML;
FinalMSG = "Test msg";
sampleMessage.HTMLBody = FinalMSG;
sampleMessage.To = "MyMail@gmail.com";
int samplePosition = (int)sampleMessage.Body.Length + 1;
int sampleType = (int)Microsoft.Office.Interop.Outlook.OlAttachmentType.olByValue;
Microsoft.Office.Interop.Outlook.Attachment sampleFile = sampleMessage.Attachments.Add(sampleSource, sampleType, samplePosition, sampleDisplayName);
sampleMessage.Save();
sampleMessage.Send();
sampleRecipient = null;
sampleFile = null;
sampleMessage = null;
sampleApp = null;

Sometimes it works Excellent and sometimes i got this error:

Retrieving the COM class factory for component with CLSID {0006F03A-0000-0000-C000-000000000046} failed due to the following error: 80080005.

i try it on computer with outlook 2010...2013..2016 and same problem.

Can not find why sometimes it works and sometimes not

thanks

Out of curiosity, why are you using the Outlook COM instead of just the System.Net.Mail library? — krillgar
If you don't mind using System.Net.Mail, you can use the following thread for reference: stackoverflow.com/questions/35108461/… — frostedcoder
ok, i try this and its working. but how to add file to this method ? and how to send mail winthout open outlook ? — Gold
@Gold: You can send it via SMTP, you can refer this for code sample: msdn.microsoft.com/en-us/library/… — frostedcoder

Luaan Luaan · Accepted Answer · 2016-02-02T14:49:32

There's a few main reasons for COM interop to fail:

The application isn't installed. This is a bit obvious, but happens often enough that it's worth mentioning. Outlook interop will only work if Outlook is installed.
The client runs in a different session or under a different user than the host. If both are just simple desktop applications, this shouldn't be a problem, but you can still check using task manager.
The COM server is 32-bit, while your application is 64-bit. Again, easy to check with task manager. Build your application as 32-bit to allow proper COM interop to work. .NET applications run in AnyCPU mode by default - 32-bit on 32-bit OSes, and 64-bit on 64-bit. So everything would work fine on a 32-bit machine, but you'll get bitness-mismatch on 64-bit Windows.

Strange error in sending the mail through C# WinForm

1 Answers