How to open .eml files using Outlook MAPI in C#?

Question

I have a C# application that reads .msg files and extracts the body and the attachments. But when I try to load a .eml file the application crashes. I am loading the files like this:

MailItem mailItem = (MailItem)outlookApp.CreateItemFromTemplate(msgFileName);
mailItem.SaveAs(fullFilename, OlSaveAsType.olHTML); // save body in html format
for(int i = 0; i < mailItem.Attachments.Count; i++)
    mailItem.Attachments[i].SaveAsFile(filename); // save attachments

This works fine with .msg files, but it doesn't work for .eml files. I don't understand why .eml files don't work, because I can open .eml files in Outlook 2010.

How can I load .eml files using the Outlook Primary Interop Assembly?

Solution 1

Try this sample code Easily Retrieve Email Information from .EML Files

Solution 2

CreateItemFromTemplate only works with the MSG/OFT files. Fot the EML files you will either need to parse the file explicitly in your code or use a third party library (such as Redemption):

The following code will create an MSG file and import an EML file into it using Redemption (RDOSession object):

  set Session = CreateObject("Redemption.RDOSession")
  Session.MAPIOBJECT = outlookApp.Session.MAPIOBJECT
  set Msg = Session.CreateMessageFromMsgFile("C:\Temp\temp.msg")
  Msg.Import "C:\Temp\test.eml", 1024
  Msg.Save
  MsgBox Msg.Subject

You can then use the message (RDOMail) to access it various properties (Subject, Body, etc.)

Comments

[CubaLibre]

Is it possible to import an eml without redemption?

[Dan Gøran Lunde]

Revised version is available: Easily Retrieve Email Information from .EML Files -- Revised codeproject.com/Articles/76607/…

[Dmitry Streblechenko]

Sure, if you parse the EML file and set various MailItem object properties one at a time.

[MGOwen]

@danglund The revised version looked more complex, was 3 largish .cs files instead of one (some containing irrelevant stuff), and wouldn't even compile for me.

[Dmitry Streblechenko]

This would cause the EML file to be displayed, which might not be what the OP wants.

[bobzer]

Hi i would like to use this code but i don't have a .msg. i need a fake .msg to import an eml ? How can i import/open an eml directly ?

[Dmitry Streblechenko]

The script above creates a temporary MSG file (you can delete it later or call Msg.Delete when you are done) so that it will have something to import an EML file into. MAPI or Outlook Object Model do not natively work with EML files - you need to have either a message in one of Outlook folders, or an MSG file.