Invalid Email Address in To Field of Send Email Smart Service

Question

I have an Array of Email Address which I am using in To field of Send Email Smart Service. Out of this array few are valid and few are invalid (Lets say wrong domain but valid format) . Email node will fail and throw com.sun.mail.smtp.SMTPAddressFailedException for invalid addresses and will pause by exception. In this case will email be surely sent to all valid addresses or the node will pause as soon as it encounters the first invalid email address. If so what will be the order in which email node will pick these email addresses as it is not sequential order in which the email addresses are picked in Array. 
 
 Thanks

Mike Schmitt · Answer

> our mail server thows an exception if an invalid domain is encountered

How does your mail server decide what is and what is not a valid domain, considering that there are millions of valid domains, and just as many (if not more) domains that are just as syntactically valid but aren't registered? Is there a whitelist or such? You might consider attempting to enforce appian-side validation to ensure domains entered are valid in the same way that the SMTP server does, if possible.

As for your question about whether the smart service will send any of the emails when it's a list of <some valid> and <some invalid> addresses - that's something I don't know and is likely buried in the engines. If you need an official answer you might consider opening a support case. However it should also be super easy to test - you only need to construct a test process model where the email smart service attempts to send a message to 2 email addresses: yours + an invalid address... if you get the email (or not), you have your answer then.