Weird Gmail Location History

Free web site (accepting donations):

Vallery.net
This application will connect to Gmail and extract all of the email addresses.
* look at every single message stored in your Gmail account
* extract all of the email addresses in the from, to, cc, bcc, reply-to, and sender headers
* create a csv file that can be imported into many common sites

Commercial software:

Gmail Extract Email Addresses Software 7.0

Extract email addresses from your Gmail email account. Save results as text files. You decide which emails to extract email data from. Extract from body or header of email message. Extract from multiple emails.

GMail Extract e-mail addresses from G-Mail Account 9

If you have a G-Mail account, and want to create a newsletter to which you can send a bunch of e-mails at once, instead of having to sort through individual e-mail addresses, then this software is for you! With this software, you can easily: Extract e-mail addresses from your g-mail account(s). You can select which standard mailboxes you want to search/extract e-mails from You can then save the resulting list to a textfile, having quickly download.

EDIT:

Email Extractor - web email addresses harvester
This is shareware. See this video for an example.

Atomic Email Hunter is an email extractor designed to harvest e-mail addresses and user names from the web sites you define (or those found basing on keywords) and using http and https protocols.

Note: I haven't tried any of them (not using gmail, sorry).

This is how to do it as of the Oct 2018 version of gmail. It requires 2 steps:

1. shift + r or shift + click Reply to "Reply with Pop Out". This will open the reply in a "pop out dialog", but it's still in the same browser tab.

2. Next, find the "Exit full-screen" button in the upper right corner.

If you do shift + click [Exit full-screen], it will open the Reply window in a new browser window.

If you do ctrl + click [Exit full-screen] (or cmd on mac), it will open the Reply window in a new browser tab.