Vert.x client for sending SMTP emails via a local mail server (e.g.
postfix) or by external mail server (e.g. googlemail or aol).
The client supports a few additional auth methods like DIGEST-MD5 and has full support for TLS and SSL and is completely asynchronous. The client supports connection pooling to keep connections open to be reused.
To use this project, add the following dependency to the dependencies section of your build descriptor:
-
Maven (in your
pom.xml
):
<dependency>
<groupId>{maven-groupId}</groupId>
<artifactId>{maven-artifactId}</artifactId>
<version>{maven-version}</version>
</dependency>
-
Gradle (in your
build.gradle
file):
compile {maven-groupId}:{maven-artifactId}:{maven-version}
You can send mails by creating a client that opens SMTP connections from the local jvm.
The client uses a configuration object, the default config is created as empty object and will connect to localhost port 25, which should be ok in a standard Linux environment where you have Postfix or similar mail server running on the local machine. For all possible properties of the config object, see below.
The client can use a connection pool of the SMTP connections to get rid of the overhead of connecting each time to the server, negotiating TLS and login (this function can be turned off by setting keepAlive = false). A client can either be shared or non-shared, if it is shared, the same connection pool will be used for all clients using the same identifier.
import io.vertx.groovy.ext.mail.MailClient
def config = [:]
def mailClient = MailClient.createShared(vertx, config, "exampleclient")
The first call to MailClient.createShared will actually create the pool with the specified config. Subsequent calls will return a new client instance that uses the same pool, so the configuration won’t be used.
If you leave out the pool identifier, a default pool will be created. Note that the clients are shared in the scope of a vertx instance only (so two different vertx will have different pools with the same identifier).
The unshared client can be created the same way leaving out the identifier.
import io.vertx.groovy.ext.mail.MailClient
def config = [:]
def mailClient = MailClient.createNonShared(vertx, config)
A more elaborate example using a mailserver that requires login via TLS
import io.vertx.ext.mail.StartTLSOptions
import io.vertx.groovy.ext.mail.MailClient
def config = [:]
config.hostname = "mail.example.com"
config.port = 587
config.starttls = StartTLSOptions.REQUIRED
config.username = "user"
config.password = "password"
def mailClient = MailClient.createNonShared(vertx, config)
Once the client object is created, you can use it to send mails. Since the sending of the mails works asynchronous in vert.x, the result handler will be called when the mail operation finishes. You can start many mail send operations in parallel, the connection pool will limit the number of concurrent operations so that new operations will wait in queue if no slots are available.
A mail message is constructed as JSON. The MailMessage object has properties from, to, cc, bcc, subject, text, html etc. Depending on which values are set, the format of the generated MIME message will vary. The recipient address properties can either be a single address or a list of addresses.
The MIME encoder supports us-ascii (7bit) headers/messages and utf8 (usually quoted-printable) headers/messages
def message = [:]
message.from = "user@example.com (Example User)"
message.to = "recipient@example.org"
message.cc = "Another User <another@example.net>"
message.text = "this is the plain message text"
message.html = "this is html text <a href=\"\">vertx.io</a>"
Attachments can be created by the MailAttachment object using data stored in a Buffer, this supports base64 attachments.
import io.vertx.groovy.core.buffer.Buffer
def attachment = [:]
attachment.contentType = "text/plain"
attachment.data = Buffer.buffer("attachment file")
message.attachment = attachment
When sending the mail, you can provide a AsyncResult<MailResult> handler that will be called when the send operation is finished or it failed.
A mail is sent as follows:
mailClient.sendMail(message, { result ->
if (result.succeeded()) {
println(result.result())
} else {
result.cause().printStackTrace()
}
})
Email fields are Strings using the common formats for email with or without real name
-
username@example.com
-
username@example.com (Firstname Lastname)
-
Firstname Lastname <username@example.com>
The MailMessage object has the following properties
-
from
String representing the From address and the MAIL FROM field -
to
String or list of String representing the To addresses and the RCPT TO fields -
cc
same as to -
bcc
same as to -
bounceAddress
String representing the error address (MAIL FROM), if not set from is used -
text
String representing the text/plain part of the mail -
html
String representing the text/html part of the mail -
attachment
MailAttachment or list of MailAttachment attachments of the message -
headers
MultiMap representing headers to be added in addition to the headers necessary for the MIME Message -
fixedHeaders
boolean if true, only the headers provided as headers property will be set in the generated message
the last two properties allow manipulating the generate messages with custom headers, e.g. providing a message-id chosen by the calling program or setting different headers than would be generated by default. Unless you know what you are doing, this may generate invalid messages.
The MailAttachment object has the following properties
-
data
Buffer containing the binary data of the attachment -
contentType
String of the Content-Type of the attachment (e.g. text/plain or text/plain; charset="UTF8", default is application/octet-stream) -
description
String describing the attachment (this is put in the description header of the attachment), optional -
disposition
String describing the disposition of the attachment (this is either "inline" or "attachment", default is attachment) -
name
String filename of the attachment (this is put into the disposition and in the Content-Type headers of the attachment), optional
The configuration has the following properties
-
hostname
the hostname of the smtp server to connect to (default is localhost) -
port
the port of the smtp server to connect to (default is 25) -
startTLS
StartTLSOptions either DISABLED, OPTIONAL or REQUIRED, default is OPTIONAL -
login
LoginOption either DISABLED, NONE or REQUIRED, default is NONE -
username
String of the username to be used for login -
password
String of the password to be used for login -
ssl
boolean whether to use ssl on connect to the mail server (default is false), set this to use a port 465 ssl connection -
ehloHostname
String to used in EHLO and for creating the message-id, if not set, the own hostname will be used, which may not be a good choice if it doesn’t contain a FQDN or is localhost -
authMethods
String space separated list of allowed auth methods, this can be used to disallow some auth methods or define one required auth method -
keepAlive
boolean if connection pooling is enabled (default is true) -
maxPoolSize
int max number of open connections kept in the pool or to be opened at one time (regardless if pooling is enabled or not), default is 10 -
trustAll
boolean whether to accept all certs from the server (default is false) -
keyStore
String the key store filename, this can be used to trust a server cert that is custom generated -
keyStorePassword
String password used to decrypt the key store -
allowRcptErrors
boolean if true, sending continues if a recipient address is not accepted and the mail will be sent if at least one address is accepted