In the film Morning Glory (2010), someone tries to duck out of Rachel McAdams’ inquiry by claiming he never got her e-mail. But she countered that her cellphone app showed he had not only received the e-mail but also opened it. Can that happen in real life? I’ve taken awhile opening some e-mails after seeing that. Have to maintain some level of plausible deniability, ya know.
Sure, but it takes a special app.
Like this.
That app sounds like the recipient has to choose whether to notify the sender. In the film, the recipient didn’t know McAdams had been notified. Can the sender ever be notified even if the recipient doesn’t choose?
Hi Sam. Depends on your email server, but yeah, definitely available as well as retrieving sent emails as long as they were unopened.
Hmmm. Sounds like I’d best continue to be careful about whose e-mails I open right away.
Just another example of The Man keepin’ us down. 
A traditional way is to embed a custom image (perhaps just of a single white pixel) in the message. The sender checks his server access log to know if and precisely when that image was read. (This won’t work if your e-mail client asks before displaying images, and you answer No.)
Can this be done with Gmail?
Are you asking if you can check recipient’s opening of messages you send from Gmail? You just need control of a website whose logs you can check, and to create one unique image (e.g. single-pixel) for each message you want to check.
(Do mail readers open images automatically? If not, instead of a single-pixel image, copy a hot model with appropriate caption. 
)
Mozilla’s Thunderbird email application/program (for desktops, anyway) has a “Never send a return receipt” setting.