Gomail.v2 - Multiple recipiens from Slice

Question

Disclaimer: I have seen a similar question in this thread: Golang multiple recipients with gomail.v2 but cannot get this to work, and do not yet have the juice to comment there asking for help. The op in that question is using os.Args[], whereas I want to use a slice stored in a config file.

I'm attempting to use the awesome gomail.v2 package to send to a list of multiple recipients contained in a slice ToMail in instance e of struct Email via my method Mail.

The compiler complains at line 37:

./mailer.go:37: not enough arguments in call to m.SetAddressHeader
        have (string, []string...)
        want (string, string, string)

How can I properly pass each recipient in my slice to the SetAddressHeader("To"... method so as to send to all recipients in slice ToMail?

What I've tried:

package main

import (
        "fmt"
        "gopkg.in/gomail.v2"
)

type Email struct {
        FromMail, FromFirstLast, Password, Subject, Body, Server string
        ToMail []string
        Port int
}

func main() {
        e := Email{FromMail: "[email protected]",
                FromFirstLast: "From User",
                ToMail: []string{"[email protected]", "[email protected]"},
                Password: "passpasspass",
                Subject: "Test",
                Body:"TEST BODY",
                Server: "foo.foomail.com",
                Port: 587,}
        err := e.Mail()
        if err != nil {
                fmt.Println(err)
        }
}

func (e Email)Mail() (error) {
    m := gomail.NewMessage()
    m.SetAddressHeader("From", e.FromMail, e.FromFirstLast)
    addresses := make([]string, len(e.ToMail))

    for i, _ := range addresses{
        addresses[i] = m.FormatAddress(e.ToMail[i], "")
    }
    m.SetAddressHeader("To", addresses...)
    m.SetHeader("Subject", e.Subject)
    m.SetBody("text/plain", e.Body)

    d := gomail.NewPlainDialer(e.Server, e.Port, e.FromMail, e.Password)
    if err := d.DialAndSend(m); err != nil {
        return err
    }
        return nil
}

Answer 1

package gomail

import "gopkg.in/gomail.v2"

func (*Message) SetAddressHeader

func (m *Message) SetAddressHeader(field, address, name string)

SetAddressHeader sets an address to the given header field.

func (*Message) SetHeader

func (m *Message) SetHeader(field string, value ...string)

SetHeader sets a value to the given header field.

The example you referenced and the documentation has, for multiple addresses:

addresses := make([]string, len(e.ToMail))
for i := range addresses {
    addresses[i] = m.FormatAddress(e.ToMail[i], "")
}
m.SetHeader("To", addresses...)

But you write, using the single address (with implicit FormatAddress) form:

m.SetAddressHeader("To", addresses...)

Error:

not enough arguments in call to m.SetAddressHeader
        have (string, []string...)
        want (string, string, string)