How to get From from Email Header (imap) in golang?

Question

go

I can not find a solution, maybe someone worked with this. I can get the header:

2020/12/14 16:19:37 entity = {{[0xc00005a680 0xc00005a640 0xc00005a600 0xc00005a5c0 0xc00005a580 0xc00005a540 0xc00005a500 0xc00005a4c0 0xc00005a480 0xc00005a440 0xc00005a400 0xc00005a3c0 0xc00005a380 0xc00005a340 0xc00005a300 0xc00005a2c0 0xc00005a280 0xc00005a240 0xc00005a200 0xc00005a1c0] map [Authentication-Results: [0xc00005a340] Content-Type: [ 0xc00005a640] Date: [0xc00005a5c0] Dkim-Signature: [0xc00005a300] From: [0xc00005a480] Message-Id: [0xc00005a600] Mime-Version: [0xc00005a540] Received: [0xc00005a440 0xc00005a280 0xc00005a200 0xc00005a1c0] Return-Path: [0xc00005a680] Subject: [0xc00005a500] To:[0xc00005a4c0] X-Mailer:[0xc00005a580] X-Yandex-Internal:[0xc00005a240] X-Yandex-Sender-Uid:[0xc00005a400] X-Yandex-Spam:[0xc00005a3-c0] X-Yandex Status:[0xc00005a380] X-Yandex-Timemark:[0xc00005a2c0]]}}

Unable to retrieve value.

Output code:

for _, r := range msg.Body {

      entity, err := message.Read(r)
      if err != nil {
        log.Fatal(err)
      }
      log.Println("entity = ",entity.Header)

Project at github.com/emersion/go-imap

Answer 1

The header type, if I'm not mistaken, should be MIMEHeader , i.e. this is a regular map[string][], where the key is the header + methods Get, Values
​​This is how you will see what is there at all (all the keys and values ​​of the map) And this is how you can get the first value of the header
log.Printf("entity: %+v\n", entity.Header)

log.Printf("entity: %+v\n", entity.Header.Get("From"))

Or all header values

log.Printf("entity: %+v\n", entity.Header.Values("To"))

More details about the methods can be found here https://godoc.org/net/textproto#MIMEHeader