package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)(^References:|\G(?!\A)).*?@\Kdomain-a\.com`)
var str = `References: <mail-1@domain-a.com> <mail-2@domain-a.com> <mail-3@domain-a.com>
Another-Header: <example@domain-a.com>
`
var substitution = "domain-b.com"
fmt.Println(re.ReplaceAllString(str, substitution))
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/