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I am using SMTP for emailing my document in PDF-eXPLODE. How do I get external emails to be delivered?


Each time I use an email address which is an external domain, the email errors. This happens also when I do a test connection.


The first thing we need to establish is a real reason for any email sending error. Open the PDF-eXPLODE configuration screen and click on the left hand side tree - 'Logging and Utilities'. This will display a logging option 'Log details of SMTP e-Mails sent', for which you must check the box, Save and Exit the Options screen.

Now re-run the Test Connection, making sure you change the Sender address to any external address like Gmail or Yahoo, one which you can access. Once you click Test Connection button on the E-Mail Connection Settings  tab on the Mail Settings menu, you would trigger an error as soon as PDF-eXPLODE attempts to send this email to the external address. Go to the Logging menu and click on the View Details Log  button, to open the log in Notepad and review the email error. Search this log to locate either error line (550 5.7.1 Unable to Relay or 501 5.1.7 Invalid Address) :

550 5.7.1 Unable to relay
Failed when sending RCPT TO: <mail@3000ad.com.au>


SmtpCmdResp: 501 5.1.7 Invalid address 
501 5.1.7 Invalid address 
Failed when sending MAIL FROM :<mail@3000ad.com.au>

If an email sent within the company is successful and one sent outside your domain is not and the error shown in the PDF-eXPLODE SMTP log is " 550 5.7.1 Unable to relay"   then you would probably have a 'Relaying' issue. This error is where MS Exchange has not been configured to send any SMTP emails to outside organizations.

What is Relaying?

In the context of emailing, "Relaying" means receive and pass on (information or a message). Relaying is when email is accepted  by the ISP or your outgoing server, and then delivered to a non-local email (destination) address. ie. Your Microsoft Exchange server has to "relay" the email back out to the ISP for onward delivery to the destination. In the past, only "open relays" existed. An open mail relay is an SMTP server configured in such a way that it allows anyone on the Internet to send e-mail through it, not just mail destined to or originating from known users.

To avoid spammers using the mail server to send email out to anyone, users are required to authenticate against the server prior to sending email. This authentication is generally the use of Logins to identify bona fide Senders. However this also extends to authenticating the source (such as the internal IP address or email sending program like PDF-eXPLODE) sending the email out through the Exchange server. Since the release of Office 2007 and Microsoft Exchange 2007, the standard default practise of allowing "open relays" has been abandoned and an explicit "SMTP connector"  must be setup to identify PDF-eXPLODE (or any email sending program) as an approved source of email sending.

This is a security measure to prevent spammers from using your SMTP server to send 'junk' or 'spam' mail out of your server's mail box. If your company uses MS Exchange or Lotus Domino to manage incoming and outgoing emails from your employee mailboxes, then you would have to configure this server to  add an SMTP connector  that will validate PDF-eXPLODE sent mail. To learn more on how to configure MS Exchange 2007 you can click this link: 

MS Exchange 2007/2010
How to Configure MS Exchange 2007/+ for SMTP email sending

If you are using  Exchange 2013 and 2016 , there are separate Internal and External SMTP relay connector configurations required.

MS Exchange 2013
How to configure MS Exchange-2013 smtp-relay-connector  

MS Exchange 2016
How to configure MS Exchange-2016 smtp-relay-connector

IBM Lotus Domino  How to Configure Lotus Domino V6.5 for SMTP email sending

MS Office 365  is a cloud based Exchange Server. To set up an SMTP relay in Office 365,  you will need to upgrade to PDF-eXPLODE V3.3.13.99 (June 2013) + or PDF-eXPLODE V4 as Office 365 requires a StartTLS explicit security connection. Details of how to set up the SMTP connection in Office365 can be sourced from  https://technet.microsoft.com/en-us/library/dn554323.aspx   (Select Option 3 /  Settings for Office 365 SMTP relay)

If you are working with  MS Exchange 2003 , then here are configuration instructions for external relaying: 

Configuring Exchange 2003 for Relaying

If you are connecting directly through your Internet Service Provider (ISP), then contact them to determine why your external bound emails are blocked.

In the case of error:  501 5.1.7 Invalid address, this is a similar Relaying issue. However, the 'fix' is different.   

Please read this article on the error and how to fix:  https://support.microsoft.com/en-au/help/944302/3rd-party-application-or-mail-server-may-fail-to-send-to-or-relay-mail  



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