Pull out emails matching critera

get_emails.fsx

#r "nuget:MimeKit"

open System.IO
open System.Text.RegularExpressions
open MimeKit


let (=~) (input: InternetAddressList) pattern =
    input
    |> Seq.exists (fun addr ->
        let m =
            Regex.Match((addr :?> MailboxAddress).Address, pattern, RegexOptions.IgnoreCase) in

        if m.Success then true else false)

let parse (parser: MimeParser) =
    try
        Some(parser.ParseMessage())
    with _ ->
        None

let getWilliamsFiles mailbox =
    use stream = File.Open(mailbox, FileMode.Open)

    let parser = MimeParser(stream, MimeFormat.Mbox)

    seq {
        while not parser.IsEndOfStream do
            yield (parse parser)
    }
    |> Seq.choose id
    |> Seq.filter (fun x -> x.From =~ "example.com" || x.To =~ "example.com")
    |> Seq.take 3
    |> Seq.iter (printfn "%A")


getWilliamsFiles
    @"B:\inbox.mbox"