Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Return error when no MX records #44

Open
wants to merge 2 commits into
base: master
Choose a base branch
from
Open

Return error when no MX records #44

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
0dc0ce3
Return error when no MX records
milesfaciane May 31, 2024
ddd9be1
Update checkmail.go
milesfaciane Jun 3, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 8 additions & 1 deletion checkmail.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,7 @@ const forceDisconnectAfter = time.Second * 5
var (
ErrBadFormat = errors.New("invalid format")
ErrUnresolvableHost = errors.New("unresolvable host")
ErrNoMXRecord = errors.New("host DNS does not have MX records")

emailRegexp = regexp.MustCompile(`(?m)^(((((((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?)|(((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?"((\s? +)?(([!#-[\]-~])|(\\([ -~]|\s))))*(\s? +)?"))?)?(((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?<(((((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?(([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+(\.([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+)*)((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?)|(((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?"((\s? +)?(([!#-[\]-~])|(\\([ -~]|\s))))*(\s? +)?"))@((((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?(([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+(\.([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+)*)((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?)|(((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?\[((\s? +)?([!-Z^-~]))*(\s? +)?\]((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?)))>((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?))|(((((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?(([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+(\.([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+)*)((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?)|(((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?"((\s? +)?(([!#-[\]-~])|(\\([ -~]|\s))))*(\s? +)?"))@((((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?(([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+(\.([A-Za-z0-9!#-'*+\/=?^_\x60{|}~-])+)*)((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?)|(((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?\[((\s? +)?([!-Z^-~]))*(\s? +)?\]((((\s? +)?(\(((\s? +)?(([!-'*-[\]-~]*)|(\\([ -~]|\s))))*(\s? +)?\)))(\s? +)?)|(\s? +))?))))$`)
)
Expand All @@ -47,8 +48,10 @@ func ValidateFormat(email string) error {
// ValidateMX validate if MX record exists for a domain.
func ValidateMX(email string) error {
_, host := split(email)
if _, err := net.LookupMX(host); err != nil {
if mx, err := net.LookupMX(host); err != nil {
return ErrUnresolvableHost
} else if len(mx) == 0 {
return ErrNoMXRecord
}

return nil
Expand All @@ -60,6 +63,8 @@ func ValidateHost(email string) error {
mx, err := net.LookupMX(host)
if err != nil {
return ErrUnresolvableHost
} else if len(mx) == 0 {
return ErrNoMXRecord
}
client, err := DialTimeout(fmt.Sprintf("%s:%d", mx[0].Host, 25), forceDisconnectAfter)
if err != nil {
Expand All @@ -78,6 +83,8 @@ func ValidateHostAndUser(serverHostName, serverMailAddress, email string) error
mx, err := net.LookupMX(host)
if err != nil {
return ErrUnresolvableHost
} else if len(mx) == 0 {
return ErrNoMXRecord
}
client, err := DialTimeout(fmt.Sprintf("%s:%d", mx[0].Host, 25), forceDisconnectAfter)
if err != nil {
Expand Down