Thank you, theducks. I just did a test to four of my Kindles (Kindle Keyboard, Kindle Voyage, my phone, and Kindle Fire) using
name@free.kindle.com over WiFi. (I know that you suggest not using free.kindle.com, but it has worked for me in the past.)
There was successful delivering of the NYT to the Kindle Keyboard, Kindle Voyage, and my phone and unsuccessful delivery to the Kindle Fire. I double checked the email address on my Kindle Fire and made sure it was correct there and on Calibre.
Here's the error message I got on Calibre. Thank you for your help!
Traceback (most recent call last):
File "site-packages/calibre/gui2/email.py", line 43, in run
File "site-packages/calibre/gui2/email.py", line 124, in sendmail
File "site-packages/calibre/utils/smtp.py", line 116, in sendmail
File "site-packages/calibre/utils/smtp.py", line 108, in sendmail_direct
IOError: Failed to send mail: error(60, 'Operation timed out')