I've just recieved my NVR-ELE16C-P4K today and I have set up 2 cameras to test (IPOB-EL3IRE).  I'm configuring the NVR via the web interface.  I've read every forum entry here that seemed even remotely applicable and I'm still stuck.  I receive the emails OK (one MD alert and one MD clear) but there is no attachment (snapshot) on either email.  Interestingly, the icon on my email client (Thunderbird) indicates that there is an attachment on each email (little paper clip icon) but as soon as I select the email this icon goes away, as if the attachment is "empty."  Here's what I've done in the web setup for the one camera (ch-1) I am testing this with:

Setup->Network-Email:  (the email test works and I get MD alerts, as stated above, so this is probably OK)
  Enable, SMTP Server (smtp.googlemail.com) Port:465
  Username, password,sender are my email identities
  SSL encrypt, subject line, and ATTACHMENT is CHECKED.
  Two recipients

Setup->Event->Video Detect->Motion Detect  (Channel 1)
  Period 1 00:00-24:00 for ALL days, checked
  Anti-dither: 5
  Region: all selected and sensitivity:60, threshold:5
  Record channel checked,  Delay 10
  Snapshot checked, setup=channel 1 selected
  Send email checked and Message checked

Setup->Camera->Encode->Snapshot (channel 1)
  Mode: Timing, Image quality:5, Interval 3SPL

Setup->Camera->Encode->Path is set to an existing subdir of my home directory.

Info->
Web: 3.2.3.55576
System Version: 3.210.0002.0, Build Date: 2015-06-17

Any help is appreciated.  Thanks.