SMTP Email Rejection Issue

[WorkinWorkin]

Hey All,

I have been working on an auto email program as a SubVi to a larger program. I am not encountering any errors through the program but the emails are not being delivered. My IT department tells me that it is something the SMTP module is sending, see below:

The results came back from the SMTP Server research… See below.

We can confirm the mail is reaching the SMTP Gateway, however, there must be something in the header or message body that the SMTP Server does not like.

The SMTP Gateway servers are configured to reject and filter all mail out that looks suspicious, unfortunately there’s not much that can be done on that end…

You will need to work with NI, to understand what the SMTP module is sending and change the method of alerting or find another way to send email alerts.

Jun 21 11:38:38 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY email@email.com [rejected]

Jun 21 11:38:38 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY email@email.com [rejected]

Jun 21 11:38:38 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY email@email.com [rejected]

Jun 21 11:38:38 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY email@email.com [rejected]

Jun 21 11:38:38 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY  [rejected]

Jun 21 11:38:38 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: possible SMTP attack: command=VRFY, count=6

Jun 21 11:38:39 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY  [rejected]

Jun 21 11:38:40 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY  [rejected]

Jun 21 11:38:41 msplin172 sendmail[3787]: u5LGccO6003787: phxceburnin-004.mfg.core.Company.com [10.72.160.109]: VRFY  [rejected]

**Company information and email addresses redacted**

Has anybody seen this issue? Is there something in the module that servers could misconstrue as harmful?

Thanks

[RavensFan]

6 messages in 1 second.  9 in 3 seconds.  Part of the error message says possible SMTP attack.

Are you sending too many messages too fast?

[WorkinWorkin]

It is a single email to multiple recipients. Also tried changing to single recipient to no avail.

[ᴮᴬᴿᵀ]

Does your SMTP server require authentication?  My company's server will not allow anonymous connections.  Also it looks like the array you have wired to the "To" field has a bunch of empty strings.  I know you said you redacted information, but are all of those filled in your application.  I copied out just the second frame of your sequence and it works fine for me (with authentication).

[WorkinWorkin]

If you mean Authentication as in User/Pass, it does not. Our "Manufacturing" server does not have individual login just individual computer names (email addresses). I'm not sure what you mean by ALL in the "To" 1D array, the counter does not end as far as I can tell but it is left blank in the example to keep it anonymous. Usually I have 4-5 individual email addresses in the 1D array. 

[ᴮᴬᴿᵀ]

In the attached image, highlighted in blue.  Those array fields are populated, but empty.  

Have you wired up the invalid recepients on the send.vi to see if the server is responding?

[WorkinWorkin]

To answer your question I deleted the 1D Array and just put in a string constant with my email, did not fix it. The server is responding that is what the original post was about, server is kicking out the email thinking it is harmful.