Are there .NET Framework methods to parse an email (MIME)?

Neil C. Obremski picture Neil C. Obremski · Nov 3, 2009 · Viewed 34.3k times · Source

Is there a class or set of functions built into the .NET Framework (3.5+) to parse raw emails (MIME documents)?

I am not looking for anything fancy or a separate library, it needs to be built-in. I'm going to be using this in some unit tests and need only grab the main headers of interest (To, From, Subject) along with the body (which in this case will always be text and therefore no MIME trees or boundaries). I've written several MIME parsers in the past and if there isn't anything readily available, I'll just put together something from regular expressions. It would be great to be able to do something like:

MailMessage msg = MailMessage.Parse(text);

Thoughts?

Answer

John Gietzen picture John Gietzen · Nov 3, 2009

I know you said no external libraries, but I have a library posted on codeplex:

https://bitbucket.org/otac0n/mailutilities

MimeMessage msg = new MimeMessage(/* string, stream, or Byte[] */);

It has been tested with over 40,000 real-world mail messages.

I'm not too happy with my namespace choice, but... I'm too lazy to change it.


PS:

Internally, my library uses these regexes as a parser:

internal static string FullMessageMatch =
    @"\A(?<header>(?:[^\r\n]+\r\n)*)(?<header_term>\r\n)(?<body>.*)\z";
internal static string HeadersMatch =
    @"^(?<header_key>[-A-Za-z0-9]+)(?<seperator>:[ \t]*)(?<header_value>([^\r\n]|\r\n[ \t]+)*)(?<terminator>\r\n)";
internal static string HeaderSeperator =
    "\r\n";
internal static string KeyValueSeparator =
    @"\A:[ \t]*\z";