I have an application hosted in an Amazon EC2 Server that uses e-mail service from a shared web host. I did this to utilize the shared hosting e-mail server and the available e-mail administration tool and webmail interface.
My application uses amazon SES to send e-mail. I just authorized SES to send mails with my domain name (by adding some entries to my dns records and confirming I'm the domain owner), and this is working ok. When I need to send a mail, I connect to SES SMTP server and send it using PHPMailer.
Everything is working ok, except my mails are getting the DOS_OUTLOOK_TO_MX flag in SpamAsssasin's, making it sometimes be classified as spam.
What this flag means? Is there some way to avoid it?
Spamassassin DOS_OUTLOOK_TO_MX rule is fired when two internal flags are set by processed message: __DOS_DIRECT_TO_MX and __ANY_OUTLOOK_MUA.
__DOS_DIRECT_TO_MX flag means that the message was sent directly from sender email client to recipient MTA server. This is usually true for internal mail but can occur in your case when a recipient also uses Amazon SES for mail processing.
__ANY_OUTLOOK_MUA flag means that the message has X-Mailer =~ /^Microsoft (?:Office )?Outlook\b/ header.
Both internal flags are harmless by themselves but their combination leads to DOS_OUTLOOK_TO_MX with high spam score. You need to check X-Mailer header of messages sent with PHPMailer. This header should be set to PHPMailer, not to Microsoft Outlook or something similar.
Related
Java 8 here, although this really is more of a generic Exchange/SMTP question I suppose.
I purchased a domain name and Office 365 support from GoDaddy, and as a result, have several email addresses through them. Let's say one of these is support#myapp.example.com.
I am writing a Java 8 app that will allow users to send emails to this support address (through the app). I will likely use the excellent Simple Java Mail library, which wraps the Java Mail API. And so somewhere in my app there will be some code that looks something like:
Email email = EmailBuilder.startingBlank()
.to("MyApp Help Desk", "support#myapp.example.com")
.withSubject("Support Ticket #12345")
.withPlainText("Something went wrong inside the MyApp!")
.buildEmail();
Mailer mailer = MailerBuilder
.withSMTPServer("smtp.host.com", 587, "user#host.com", "password")
.withTransportStrategy(TransportStrategy.SMTP_TLS)
.withProperty("mail.smtp.sendpartial", true)
.buildMailer();
mailer.sendMail(email);
Pretty straight-forward stuff, right? Except I'm confused about one simple thing: which SMTP server am I using here? Would I use the Microsoft Exchange server that my GoDaddy account provides me, or would I choose something else?
That depends a little bit on what you want to do.
If you just want to make one attempt to send the mail, you connect to the mail server that accepts mail for support#myapp.example.com. It sounds like this is an office365 server owned by Microsoft that accepts mail for myapp.example.com. There should be public DNS records for that domain. I haven't used the Simple Java Mail library, but from your pseudocode, I assume it does the DNS lookups for you.
It sometimes happens that an application encounters errors when trying to send an email. For example, somebody could restart your app server in the middle of the smtp conversation, or reboot your router, or something else. It's pretty common to use a Mail Transfer Agent (MTA) such as Exchange to help make this process more robust. If the MTA fails on the first delivery attempt, it will retry delivery for some configurable period of time. In your case, you could send the email to your Exchange server, and it would route the email to myapp.example.com.
(In this case, Exchange is sort of acting as a Mail Submission Agent (MSA), but that's kind of a nitpick.)
Hope this helps.
So when I try to send mails with Laravel's mail facade, I can only send within our company domain, when trying to send E-mails to either gmail or outlook, the mail never gets deliviered, but if I use outlook, the mail is delivered instantly.
I have turned everything upside down to figure out what it can be, but I cant find anything that cause this issue, not even a single trace of my app sending "non-internal" mails in the exchange logs.
Our company uses an Exchange 2003 server, I have checked the logs, no trace of (Out of company) mails are there
Im on a 20 hour streak, sorry for any confusion
/Tarre
The issue was that our Exchange SMTP relay didnt have the correct connectors and configuration.
To use exchange with SMTP.
Add a Connector bridge between your Exchange server and the Virtual SMTP server.
Configure "trusted" IP's.
Everything is done in the Exchange Server Management part.
I am using Spring JavaMail for my Email communication application. How Can achieve the functionality that when a email delivery fails due the reason of wrong email address?
Achieving this reliably is not trivial. The protocol specs for SMTP in RFC 821 specifies a number of return codes. Notably 550 is what an SMTP server should return when attempting to send an email to a nonexistent address. I say should because most public-facing SMTP servers won't do this - they either quietly accepts the message and then drops it or, if they are a little more good-mannered, accepts the message but sends a "delivery failed" notice back to the sender ("from" address). Public services like MSN and Gmail will also blacklist senders if they send enough emails to non-existing addresses to prevent spam.
The reason for this is to prevent email-fishing and spamming.
So what you can do is to
Check for SendFailedException in your code. This will only work for servers that follow the SMTP specifications and actually send an error code back. Like I said, very few public servers actually do this.
Set up a proper mailbox for the address you use as sender and monitor that inbox for delivery failed notices. Note thought that these need not follow any common pattern, which is why this is non-trivial.
For the email servers that doesn't give any notice, you really have no way of knowing.
This is one of the reasons why companies buy mass emailing services from dedicated providers, since they have all these things already built to measure bounce-rate etc. But even with those, it's never going to be 100% accurate.
These FAQ entries might help as well:
If I send a message to a bad address, why don't I get a SendFailedException or TransportEvent indicating that the address is bad?
When a message can't be delivered, a failure message is returned. How can I detect these "bounced" messages?
We have a new Exchange server and use SMTP to send mails over it. This works so far, but we have no idea how the SMTP mail can be configured so that the outbox in Outlook 2003 of the sender account shows this mail. Is this only possible using MAPI or other mail client protocols?
Yes, email sent via SMTP will not be stored in the Exchange database. The simple way to work around it would be to automatically BCC the sender on any email sent via SMTP. It wouldn't be perfect as it would look like an incoming email, but at least the information would be there.
There might be addon products that you could buy that would listen in on any SMTP traffic and automatically create "sent items".
But the best solution would be something like Exchange Web Services, CDO or MAPI (depending on what your needs are and what software versions you're using).
If the accounts are IMAP accounts, you can use that to put the mail into the Sent folder. Otherwise, you'll have to use the Microsoft protocols like MAPI.
I am trying to send mail from a local iis app using localhost as my smtp server after installing free smtp but I am getting the following error:
Mailbox unavailable. The server response was: Invalid
recipient: 'validAddress'#hotmail.com
Any idea what the problem could be?
it sounds like your free (3rd party) smtp app is not leaving your network and might be trying to see if it has that mailbox itself. Try and see if there is a setting to allow the smtp server to access external connections, etc. What is the name of the free smtp app, btw?
Alternatively, can u use the built in SMTP mail provider, built into iis? do you know how to use that, instead of this 3rd party app.
It looks more like the SMTP service needs to be configured to "Relay" email... Usually this involves telling it what YOUR mail domain is, and then any mail destin for a domain other than it's own will cause it to go out to the world, and try to relay the message to the real server.
But, be careful! This is how spammers exploit email servers. They look for SMTP listeners that will relay for them. You want to make sure yours will only accept relay mail from "localhost", or whatever machine will be connecting to it to do the sending.
A more secure way is to block port 25 inbound at your firewall to this box, so this SMTP server is not visible to the outside world.
Write and test a simple smtp sender in C. It needs 3 minutes with RFC
Use Wireshark to see what comes on the wire between your application and the SMTP server.