Getting extension from a given mime type

[jacargentina]

Is your feature request related to a problem? Please describe.
I have an Image instance, and I'm. detecting its mime type, then I need to build a "filename" for it from a given title string; I need to put the right extension for the mime so when I send that content via WordpressPCL library, It gets correctly detected and processed.

var image = ....;
var mimeType = ImageCodecInfo.GetImageEncoders().First(codec => codec.FormatID == image.RawFormat.Guid).MimeType;
var filename = ...

I'm looking on how to reuse MimeTypes class from this MimeKit as it is already a dependency on my c# project for email; but it does only the reverse thing (from a filename get the mime type);

Describe the solution you'd like
Would be nice to to the other way too; from a given mime type, get the extension; so I can build the correct filename.

Describe alternatives you've considered
Copy and paste the already existing mapping dictionary from MimeTypes on my code.......

[jacargentina]

I can add another dependency to my project like this one https://github.com/samuelneff/MimeTypeMap

But as I stated previously, having already MimeKit , would be nice to avoid more dependencies and have a new method on it.

[wartab]

It seems to me that this is completely out of scope for a library like MimeKit. MimeKit's purpose is to parse and also build MIME messages.
Guesstimating what file extension could be associated with a certain media type has nothing to do with that.

[jacargentina]

@wartab Look MimeTypes.GetMimeType. Basically that method is doing a guessing for the mime type by looking at the filename.

I think the reverse is in scope for the library just because the code is already there

[jstedfast]

Implemented.