"Send email" VI failing with no error message, on some computers

[Amanda.Ison]

I am trying to set up an automated email alert across multiple test PCs using "send email" vi with TLS/SSL and login. Strangely, the vi behavior depends on the computer I use it on. Behavior across 3 computers is listed below.

Other details:

- "Allow less secure apps" is enabled in gmail. 

- Previously, some of the computers were not able to connect to "telnet smtp.gmail.com 587", but our network admin changed something, and now all of them are able to successfully connect. However, the success of the "send email" vi was not affected.

- I've tried specifying the IP address and it doesn't seem to have an effect (as long as the PC can connect to the internet). When the previous issue with connecting to "telnet smtp.gmail.com 587" occurred, Computer 1 could not connect when set to dynamic IP, but now that issue has been resolved.

- Disabling firewall also has no effect. 

Computer 1:

VI works on LAN. 

No wifi option.

Computer 2:

VI does not work on LAN. No error message

VI does not work on wifi. No error message

Computer 3:

VI does not work on LAN. Error 59

VI works on wifi

The fact that computer 3 works on wifi but not on LAN leads me to believe that this is still a network issue. Our network admin is offsite, however, and I've run out of things I know how to check.

Edit: by LAN, I mean "ethernet"

[Mark_Yedinak]

gmail gets a bit weird about the authentication. Are the computers all using the same source address? Is the source addressa gmail account? Did you authenticate LabVIEW, or your application name, as a valid source to send email via gmail? You are probably getting blocked on gmail's side and it is not reporting an error because the VI was successful in actually sending the message, it's just that gmail is not delivering it. They do this to reduce spam bots effectiveness.

[Amanda.Ison]

Hi Mark,

Most of my network knowledge comes from the past week, so I apologize if this is stuff I should know. Not sure what "source address" means, but "allow less secure apps" should have removed any security problems Gmail had have with LabVIEW. 

To my understanding, the computers are all using the same server and network. The IP addresses are the same for ethernet except for the last number (#.#.#.x). Same for the wifi, except the first 3 numbers are different. 

The "public IP address" is constant for all computers I checked (#.#.#.#).

[Mark_Yedinak]

Source address is the sender's e-mail address. I should have been more clear about that. I have run into problems with gmail in the past. I had to get a to get a key to allow me to successfully send email via gmail. I forget the exact method I had to use to get the key but it was via my gmail profile.