Client Side Only standalone Smtp Client/relay, for sending mails directly - smtp

Usually, when you send an e-mail (with Thunderbird or Outlook), you don't send it directly.
example: I have a gmail address and I want to send an e-mail to a myopera address. The process will be:
user->gmail server(gmail-smtp-in.l.google.com)->myopera server(in1.smtp.messagingengine.com)->final user who'll download it's email with pop/imap.
One of the inconvenient is the size: Imagine you have attachment of 50Mb: the limit of myopera is 60MB; but the limit of gmail is 25MB,So the mail will be refused whereas it would be accepted if it was send directly to myopera.
But I saw with telnet that, it is possible to send mail directly with SMTP commands.
I want to write a client-side Only web application which would convert a mail in a set of SMTP commands for sending it. I should be very basic and not support encryption
I don't know how to create a TCP connection from a client, so, here's my questions: Does a library already exist? If not, what I should use? I've read about the existence of WebSockets but that Ajax would be more universal.
Also, most of the actuals implementations of WebSocket I saw, don't work in my latests versions of web browser despite the fact they 'support it'. There's also the raw Socket API from the W3c (I've no idea of the web browsers which actually support it).So, I would like to not avoid statements telling it is impossible to create near raw TCP/UDP session. Since it is possible, I can't imagine nobody created a kind of library for dealing with protocols

You should take an alternative route.
If i had that issue i would still use a server side component of some sort, and just have the server contact to receiving mail server directly.
Given the email: "someuser#somedomain.tld" you could do a DNS MX record lookup on "somedomain.tld" and find the receiving mail server say "mail.somedomain.tld", then you could tell your mail send component to send the email directly to "mail.somedomain.tld", that way you would have an immediate feedback on whatever the mail went through or not.

For Objective-C you may use https://github.com/jetseven/skpsmtpmessage
By looking at the source you see how SMTP works.

Related

Is there a way to force GMail/Google Apps SMTP server to not store sent messages?

Perhaps a special command or message header in order to be able to tell Google to not store a message sent using their SMTP server in the respective user's Sent mailbox.
There is no way to prevent the message from being saved to Sent. However, you can connect via IMAP after the send and delete the message from the Sent folder. Assuming you are using OAuth authentication, the same scope you use for SMTP allows you to connect via IMAP.
I was also stucked in this kind of scenario some time back, for me I could not find any standard API to solve this. But as a workaround I have created a rule which deletes all the mails which appears in Sent Folder. But beware of IMAP protocol, it allows users to store their there sent messages in custom folders also.

Provide email certificate in html mailto link

I would like to know if it's possible to provide an email certificate (signed by a recognised CA) so the user clicking on the mailto link can send encrypted email to the owner of the cert ?
hello#gmail.com
Is there any way to do that using the mailto link or using some JS ? Given the mailto link is handled by a local email client, should be possible ?
If there is no direct way to do this, how to make it?
One option is a web form for message sending, served via HTTPS. The server-side handler of the form would compose an encrypted mail on the server and then send it via SMTP. This provides almost the same level of security as direct encryption (given that your server is secure). Unfortunately there's no other simple way to do what you want. Of course, you can put a link for your .cer file download and tell the user to download the .cer file and use it to compose an encrypted mail, but how would you deal with GMail users and mobile users? Web form is more flexible and easier to use for the sender.
You can look up what you according to the current specification can do with a mailto URL in RFC 2368. You'll see that it only refers to the construction of the mail text and headers, not their encoding or encryption. There may be extensions for some mail clients, but that's not something one should generally count on.
Furthermore, Web mail users generally will have problems with such links anyways. Thus, for a solution that has to be usable by anyone, a scheme counting on some client side program is not a good choice.
Thus, some Web form as mentioned by #Eugene accessable only via https would best serve your requirements.

How we can send small form in Email using AS3

I create small form (Name, email, Subject, Message) in Flash. Want to send this by email using AS3 code.
Can we use this offline? Like, we fill all the detail and after submit then its go online and receive the detail in email
as #esimov said, security is not major concern then you have to use SMTPMailer, because your mail send in pure text form to the e-mail server. but if you want to use SMTPMailer then you can use some encryption and decryption method in it. This encryption packet with key are traceable. so If security is major concern then you must use airxmail written in actionscript so you can send and receive mail with SMTP, POP3, IMAP4 protocol. best example are given to send and recieve a mail.
May this will help you.
If you want to use an email client directly using Flash technology you need to stick with Flex. It has a robust backend interaction and even more it allows to do some cross scripting interactions.
However if you wish to use Flash and not Flex, actually there is an email sending application called SMTPMailer which sends attached files through emails with the Socket class available in the Player 9 and AS3. Please note, that for security reason is always better to send emails from the server side of the application. So another possibility would be to integrate the email sending part in a server side script.

Sending emails through SMTP and testing

I've got a PHP app with an invitation system where users can invite other users to try the service. Internally we use google apps for our domain to send/receive emails (mydomain.com).
1) My question is, can I send emails from my server with the from address being invite#mydomain.com? I am worried about the emails being blocked/ignored by the destination server. I am aware that it is possible to send the emails by configuring my php installation to use google smtp server, but there is a limit of 500 emails a day, which is not very scalable.
I don't really know that much about sending emails and why/how they are blocked/considered spam. I'd appreciate any good advice/tips you can give me.
2) What is a good way to test to see if the email portion of my app is working without installing it on my live server. Can I just setup an smtp server on my desktop and send mails this way? Can you recommend any other good ideas for testing. I'll basically be sending just a few emails to my personal webmail accounts to make sure that everything works.
Thanks,
Bill
1) My question is, can I send emails
from my server with the from address
being invite#mydomain.com? I am
worried about the emails being
blocked/ignored by the destination
server. I am aware that it is possible
to send the emails by configuring my
php installation to use google smtp
server, but there is a limit of 500
emails a day, which is not very
scalable.
I don't really know that much about
sending emails and why/how they are
blocked/considered spam. I'd
appreciate any good advice/tips you
can give me.
There is a way track if mail has been bounced (there are more than 10 possible bounce reasons!). You can set the return-path header in your outgoing emails. Best practice is to specify a different mail address in the return-path. When e-mails are getting bounced for whatever reason, a notification will be sent to this address. Additionally you can have for example a (PHP) cron job that connects using IMAP to the bounced email account and do something with the bounced e-mails. This is a pretty reliable way to track the status of your sent emails.
Additionally, in order to minimize the chance your e-mail will get blacklisted you could think about signing your e-mails using a certificate (you can get one for free for personal usage. A commercial one may cost you around 25 dollars a year)
2) What is a good way to test to see
if the email portion of my app is
working without installing it on my
live server. Can I just setup an smtp
server on my desktop and send mails
this way? Can you recommend any other
good ideas for testing. I'll basically
be sending just a few emails to my
personal webmail accounts to make sure
that everything works.
You can actually send a test email from everywhere as long as the outgoing SMTP port (25) is not blocked. If you have an own smtp server with username/passwd authentication enabled, you will be able to send e-mails from everywhere using the these credentials/settings. In all other cases, you will have to use the smtp of your internet provider to send emails.
To address the second part (as Eric pointed out, you'll have better luck at serverfault.com with the first part), any locally hosted SMTP server should be able to do the trick, and there are plenty available for any given OS. Google can help you there.
The main thing you'll want from a local SMTP server is detailed logging. It's entirely possible that the local server could fail/refuse to deliver the message to its intended destination for any number of reasons (again, serverfault.com), but that's outside the scope of testing the code's delivery of the email to the SMTP server.
If it does properly forward the test message to you, great. But if it doesn't, you just want to be able to see in the server's logs that it received the message correctly and was able to process it. Whatever that processing accomplished is a separate issue.
For email testing I use Pappercut. It's easy to use but some antivirus may not like you opening port 25.
I use Dumbster for testing. I will catch the emails, then my test code can check the content.
To avoid spam, there are a number of things you have to do, and I'm not sure I've found them all. Make sure that your IP is registered, and that a reverse lookup returns the right domain.
1) Sending:
This is a good article describing some of the pitfalls around sending email http://www.codinghorror.com/blog/2010/04/so-youd-like-to-send-some-email-through-code.html
Check out the comments too.
2) Testing:
Disclaimer - I work for the company behind the service linked to below.
If you would rather not set up your own smtp server you can use a hosted email testing service like Clickity
You can create as many test email addresses as you like or configure your app to point directly at our smtp server. You can then view the complete email on our site as part of your manual testing or automate the tests it via our API.

Retrieve SMTP response of a mail

Is it possible to retrieve the SMTP response of a mail. For example, I am sending a mail to non existing email id. Surely our server will send us a mailer daemon failure mail to our mail id. I need to capture that failure mail.
How its possible? please explain me. Some time we may enter more than one non existing email id, so i have to retrieve all the failure mail alone for every corresponding emails
Please guide me!
Thanks in advance,
Praveen J
I think I understood your question correctly now. As I understand, you are writing an application to send mail. And in your application, whenever you send a mail, you also want verify that if mail was delivered and also if it was not delivered then you want to get hold of the failure message in your application. Is that how you mean?
Well, if that is how you mean, then I think it is impossible to track the mail status with your apllication code. For instance if you are using java sendMail in your apllication you can only ensure that the send happened from your code successfully(without any send exceptions like java.net.SocketException or javax.mail.MessagingException). But, you can never ensure if the mail really reached the recepient. i.e. you can never track in your application if the mail was rejected due to wrong recepient address or any other error like illegal attachment at receipient mail server or errors like blocked sender id etc.
That is because any such error condition will be communicated by the receipient mail server to the sending mail server the information of which is present in the sent mail's header.
Does that answer your question? (Or did I understand your question correctly? ;-))
I am not sure if I am getting your question right. If you send an email to any non existent address say xxx#gmail.com from your address yyy#yourhost.com, the mail server at gmail.com replies to the mail server at yourhost.com with failure message and reason, with your delivery address and you receive the fialure mail automatically. you don't have to do anything extra in this.
If you are talking about seeing mail headers, then it depends on which client you are using. For instace, if you are using MS outlook, you can right-click on the message and click options and then see internet headers section to get mail headers. If you are using some web based mail then i am sure there will some option to view detailed mail headers.
The bounced messages are going to return to a mailbox. You should be able to configure that mailbox by properly setting the headers on the messages you send out. You would then need to monitor that mailbox, or have that mailbox deliver the messages to your program.
I would suggest you consider using VERP for all messages you send out. It will make it much easier for you to identify which email address a particular bounce belongs too. To do this you would need control of your mail server though. It takes some work configuring things.
To answer the question with more detail you need to tell us how your are sending messages, what type of mail server you are running, and how much control you have over the mail server.
On Unix, you can use "procmail" for this. Procmail is a service which can intercept your mails and process them following rules.
If you can access your mail my IMAP, I suggest to look at the Python module imaplib.