README
¶
email sending library
The library is a wrapper around the stdlib net/smtp
simplifying email sending. It supports authentication, SSL/TLS,
user-specified SMTP servers, content-type, charset, multiple recipients and more.
Usage example:
client := email.NewSender("localhost", email.ContentType("text/html"), email.Auth("user", "pass"))
err := client.Send("<html>some content, foo bar</html>",
email.Params{From: "me@example.com", To: []string{"to@example.com"}, Subject: "Hello world!",
Attachments: []string{"/path/to/file1.txt", "/path/to/file2.txt"},
InlineImages: []string{"/path/to/image1.png", "/path/to/image2.png"},
})
options
NewSender
accepts a number of options to configure the client:
Port
: SMTP port (default: 25)TLS
: Use TLS SMTP (default: false)STARTTLS
: Use STARTTLS (default: false)InsecureSkipVerify
: skip certificate verification (default: false)Auth(user, password)
: Username and password for SMTP authentication (default: empty, no authentication)LoginAuth
: Use LOGIN mechanism instead of PLAIN mechanism for SMTP authentication, e.g. this is relevant for Office 365 and Outlook.comContentType
: Content type for the email (default: "text/plain")Charset
: Charset for the email (default: "utf-8")TimeOut
: Timeout for the SMTP connection (default: 30 seconds)Log
: Logger to use (default: no logging)SMTP
: Set custom smtp client (default: none)
See go docs for Option
functions.
Options should be passed to NewSender
after the mandatory first (host) parameter.
sending email
To send email user need to create a sender first and then use Send
method. The method accepts two parameters:
- email content (string)
- parameters (
email.Params
)type Params struct { From string // From email field To []string // From email field Subject string // Email subject UnsubscribeLink string // POST, https://support.google.com/mail/answer/81126 -> "Use one-click unsubscribe" InReplyTo string // Identifier for email group (category), used for email grouping Attachments []string // Attachments path InlineImages []string // Embedding directly to email body. Autogenerated Content-Id (cid) equals to file name }
See go docs for Send
function.
technical details
- Content-Transfer-Encoding set to
quoted-printable
- Custom SMTP client (
smtp.Client
from stdlib) can be set by user withSMTP
option. In this case it will be used instead of making a new smtp client internally. - Logger can be set with
Log
option. It should implementemail.Logger
interface with a singleLogf(format string, args ...interface{})
method. By default, "no logging" internal logger is used. This interface is compatible with thego-pkgz/lgr
logger. - The library has no external dependencies, except for testing. It uses the stdlib
net/smtp
package. - SSL/TLS supported with
TLS
option (usually on port 465) as well as withSTARTTLS
(usually on port 587).
limitations
This library is not intended to be used for sending a lot of massive emails with low latency requirements. The intended use case is sending simple messages, like alerts, notification and so on. For example, sending alerts from a monitoring system, or for authentication-related emails, i.e. "password reset email", "verification email", etc.
Documentation
¶
Overview ¶
Package email provides email sender
Index ¶
- type Logger
- type Option
- func Auth(smtpUserName, smtpPasswd string) Option
- func Charset(charset string) Option
- func ContentType(contentType string) Option
- func InsecureSkipVerify(enabled bool) Option
- func Log(l Logger) Option
- func LoginAuth() Option
- func Port(port int) Option
- func SMTP(smtp SMTPClient) Option
- func STARTTLS(enabled bool) Option
- func TLS(enabled bool) Option
- func TimeOut(timeOut time.Duration) Option
- type Params
- type SMTPClient
- type Sender
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Logger ¶
type Logger interface {
Logf(format string, args ...interface{})
}
Logger is used to log errors and debug messages
type Option ¶
type Option func(s *Sender)
Option func type
func ContentType ¶
ContentType sets content type of the email
func InsecureSkipVerify ¶ added in v0.5.0
InsecureSkipVerify skips certificate verification
type Params ¶
type Params struct { From string // From email field To []string // From email field Subject string // Email subject UnsubscribeLink string // POST, https://support.google.com/mail/answer/81126 -> "Use one-click unsubscribe" InReplyTo string // Identifier for email group (category), used for email grouping Attachments []string // Attachments path InlineImages []string // InlineImages images path }
Params contains all user-defined parameters to send emails
type SMTPClient ¶
type SMTPClient interface { Mail(from string) error Auth(auth smtp.Auth) error Rcpt(to string) error Data() (io.WriteCloser, error) Quit() error Close() error }
SMTPClient interface defines subset of net/smtp used by email client
type Sender ¶
type Sender struct {
// contains filtered or unexported fields
}
Sender implements email sender