mydigitalstructure enables you to send transaction emails using the MESSAGING endpoint and bulk (news) emails using the NEWS endpoint.

When an email is sent, the email server responsible for the domain of the intended recipient checks the email address to see if it is valid, it also checks if the originating servers IP address is on a "blacklist".  If the email address is not valid it sends back an email saying it was "bounced", it can also (as a internet wide anti-SPAM measure) send a message with the originating servers IP address to what is called a blacklist server.  If the blacklist server gets enough of these messages it will then add the originating servers IP address to a globally accessible "blacklist".

Given that email servers check this list before accepting an email, you can end up in the situation when done of your emails get delivered.

To prevent your sending server from being blacklisted you can (before sending) verify that an email address is valid with the server that would eventually receive the email, and if not valid not send the email.

To do this you can use a web services specifically designed for this purpose - typically they allow you to check an individual email or as a batch file.

SOME VERIFICATION WEBSERVICES (not an endorsement) API Docs API Docs API Docs API Docs


Email Verification

NEWS Endpoint
Getting started with own SMTP sending service
Blacklisting wikipedia
Blacklisting Checker