if you make the screens you can always test the smtp by a telnet ( too verify connectifity ) ( its from your pc but still it helps debugging )

assuming you run windows

in a dos prompt enter

telnet youremailprovidersmptdomain 25
so telnet myemailprovider 25

you should get an answer from the smtp server exitting by exit or quit or just closing the window
this should work if plc email sending works but its just to be sure.

should you not have telnet ( you can install it via control panel programe windows programmes ( or whatever ) and then select telnet client.