Java validate SMTP server using telnet
i'm using a library for validating SMTP connection to test invalid mail domains to avoid sending mails and bounce, simply i'm using telnet to simulate MAIL FROM: <Address>
and RCPT TO: <Address>
using BufferedWriter
and BufferedReader
as follows:
private static void send(BufferedWriter wr, String text)
throws IOException
wr.write(text + "rn");
wr.flush();
return;
private static int receive(BufferedReader in) throws IOException
String line = null;
int eCode = 0;
while ((line = in.readLine()) != null)
String pfx = line.substring(0, 3);
try
eCode = Integer.parseInt(pfx);
catch (Exception ex)
eCode = -1;
if (line.charAt(3) != '-') break;
return eCode;
calling just as follows:
Socket skt = new Socket("gmail-smtp-in.l.google.com", 25);
BufferedReader bufferedReader = new BufferedReader (new InputStreamReader(skt.getInputStream()));
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
send(bufferedWriter, "MAIL FROM: <Address>");
int status = receive(bufferedReader);
send(bufferedWriter, "RCPT TO: <Address>");
status = receive(bufferedReader);
the only problem i'm facing with this approach is performance, as MAIL FROM
CMD typically takes 10 sec and RCPT TO
CMD takes 20 sec (on terminal)
which is too much, is there's an idea of how to do that fast or use another mechanism to achieve that correctly in 1 or 2 seconds maximum ?
java performance smtp telnet email-bounces
add a comment |
i'm using a library for validating SMTP connection to test invalid mail domains to avoid sending mails and bounce, simply i'm using telnet to simulate MAIL FROM: <Address>
and RCPT TO: <Address>
using BufferedWriter
and BufferedReader
as follows:
private static void send(BufferedWriter wr, String text)
throws IOException
wr.write(text + "rn");
wr.flush();
return;
private static int receive(BufferedReader in) throws IOException
String line = null;
int eCode = 0;
while ((line = in.readLine()) != null)
String pfx = line.substring(0, 3);
try
eCode = Integer.parseInt(pfx);
catch (Exception ex)
eCode = -1;
if (line.charAt(3) != '-') break;
return eCode;
calling just as follows:
Socket skt = new Socket("gmail-smtp-in.l.google.com", 25);
BufferedReader bufferedReader = new BufferedReader (new InputStreamReader(skt.getInputStream()));
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
send(bufferedWriter, "MAIL FROM: <Address>");
int status = receive(bufferedReader);
send(bufferedWriter, "RCPT TO: <Address>");
status = receive(bufferedReader);
the only problem i'm facing with this approach is performance, as MAIL FROM
CMD typically takes 10 sec and RCPT TO
CMD takes 20 sec (on terminal)
which is too much, is there's an idea of how to do that fast or use another mechanism to achieve that correctly in 1 or 2 seconds maximum ?
java performance smtp telnet email-bounces
add a comment |
i'm using a library for validating SMTP connection to test invalid mail domains to avoid sending mails and bounce, simply i'm using telnet to simulate MAIL FROM: <Address>
and RCPT TO: <Address>
using BufferedWriter
and BufferedReader
as follows:
private static void send(BufferedWriter wr, String text)
throws IOException
wr.write(text + "rn");
wr.flush();
return;
private static int receive(BufferedReader in) throws IOException
String line = null;
int eCode = 0;
while ((line = in.readLine()) != null)
String pfx = line.substring(0, 3);
try
eCode = Integer.parseInt(pfx);
catch (Exception ex)
eCode = -1;
if (line.charAt(3) != '-') break;
return eCode;
calling just as follows:
Socket skt = new Socket("gmail-smtp-in.l.google.com", 25);
BufferedReader bufferedReader = new BufferedReader (new InputStreamReader(skt.getInputStream()));
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
send(bufferedWriter, "MAIL FROM: <Address>");
int status = receive(bufferedReader);
send(bufferedWriter, "RCPT TO: <Address>");
status = receive(bufferedReader);
the only problem i'm facing with this approach is performance, as MAIL FROM
CMD typically takes 10 sec and RCPT TO
CMD takes 20 sec (on terminal)
which is too much, is there's an idea of how to do that fast or use another mechanism to achieve that correctly in 1 or 2 seconds maximum ?
java performance smtp telnet email-bounces
i'm using a library for validating SMTP connection to test invalid mail domains to avoid sending mails and bounce, simply i'm using telnet to simulate MAIL FROM: <Address>
and RCPT TO: <Address>
using BufferedWriter
and BufferedReader
as follows:
private static void send(BufferedWriter wr, String text)
throws IOException
wr.write(text + "rn");
wr.flush();
return;
private static int receive(BufferedReader in) throws IOException
String line = null;
int eCode = 0;
while ((line = in.readLine()) != null)
String pfx = line.substring(0, 3);
try
eCode = Integer.parseInt(pfx);
catch (Exception ex)
eCode = -1;
if (line.charAt(3) != '-') break;
return eCode;
calling just as follows:
Socket skt = new Socket("gmail-smtp-in.l.google.com", 25);
BufferedReader bufferedReader = new BufferedReader (new InputStreamReader(skt.getInputStream()));
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
send(bufferedWriter, "MAIL FROM: <Address>");
int status = receive(bufferedReader);
send(bufferedWriter, "RCPT TO: <Address>");
status = receive(bufferedReader);
the only problem i'm facing with this approach is performance, as MAIL FROM
CMD typically takes 10 sec and RCPT TO
CMD takes 20 sec (on terminal)
which is too much, is there's an idea of how to do that fast or use another mechanism to achieve that correctly in 1 or 2 seconds maximum ?
java performance smtp telnet email-bounces
java performance smtp telnet email-bounces
asked Nov 14 '18 at 21:05
Bersius AjaxBersius Ajax
83
83
add a comment |
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53308713%2fjava-validate-smtp-server-using-telnet%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53308713%2fjava-validate-smtp-server-using-telnet%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown