I'm not sure I understand what "3 months of email addresses" means.

Have a look at this add-on.

https://nic-nac-project.org/~kaosmos/index-en.html#eac

You can sort your messages by date, select those for the period that you are interested in, and use the add-on to extract addresses from those messages.

This add-on:

https://addons.mozilla.org/en-US/thunderbird/addon/gmailui/

makes it possible to isolate messages with dates in a specified range, though it's a bit of a learning curve to make it work.

Both of these methods assume all the relevant messages are in one folder. If they are spread about over multiple folders then I'd think about using a Saved Search to collate the relevant messages into a virtual folder.

https://support.mozilla.org/en-US/kb/using-saved-searches

Having used the add-on to copy the required addresses to a new address book, you can export that address book to a CSV file. I can't see a way to go straight from messages to CSV file.

Thanks for your answer. To be more clear, 3 months of emails means that I want to take a number of emails from a 3-month period and extract/harvest the email addresses. It's easy to order the emails by date, simply clicking on the date column does that. But how do you extract the email addresses from the 3-month group? And yes, they are in the same folder.

Use the Add-on in my first link.

Apparently the Email Address Crawler is not compatible wit the current version of TB.

I don't usually recommend add-ons that I haven't tried myself. I use this add-on here and I know that it does work in the current version of Thunderbird.

Users who say an add-on won't install or is incompatible often turn out to be trying to install it into Firefox (not Thunderbird) or are treating it as a Windows application.

How to install add-ons: http://xenos-email-notes.simplesite.com/416814616

So I downloaded the add-on you suggested, but there are no instructions as to how to use it. Also, in the "More" section of the add-on it says:

!!!!!!You have to download this addon version here: https://addons.mozilla.org/de/thunderbird/addons/versions/9995#version-2.0.0

This takes me to a site in German, I have no idea if I'm supposed to download/install this also, whatever it is.

So I downloaded the add-on you suggested, but there are no instructions as to how to use it. Also, in the "More" section of the add-on it says:

!!!!!!You have to download this addon version here: https://addons.mozilla.org/de/thunderbird/addons/versions/9995#version-2.0.0

This takes me to a site in German, I have no idea if I'm supposed to download/install this also, whatever it is.

You appear to have gone through to the abandoned earlier version. Try using kaosmos' build:

https://nic-nac-project.org/~kaosmos/emailcrawler-5.1.2.xpi

Right click that link, use Save Link As, download it. Use the gear button on Thunderbird's add-ons page to install from the downloaded file.

Or drag the downloaded xpi file onto Thunderbird's add on page, or in Windows, you may be able to just drag my link onto the add-ons page.

I used your link to download the app, but in the 'more' section the app says:

!!!!!!You have to download this addon version here: https://addons.mozilla.org/de/thunderbird/addons/versions/9995#version-2.0.0

which takes me to the site in German, exactly as the last version I downloaded.

Let me explain why I'm trying to for this: i have a newsletter and every few months I need to sweep my inbox to see hat new emails I need to add. Maybe the way to go is to simply make anew address book of all the emails of the past three months, then export that address book? Does TB eliminate duplicate emails from the address book?

thanks

There's some software advertised here that might do what you want: http://download.cnet.com/Thunderbird-Email-Address-Extractor/3000-2369_4-76146891.html It says it's free to try, with limited functionality; you would have to pay for a fully working version. I've no idea if it works and I'm not endorsing or recommending it in any way: I just did a google search around your problem and this result came up.

I have shown you that you need v5.1.2. Don't you think that would supersede old instructions to use v2.0.0? Kaosmos took over development of this abandoned add-on and added it to his own site.

Go here: https://nic-nac-project.org/~kaosmos/index-en.html#eac

Click where it says "Download". Ignore the link to the obsolete version on AMO.

Over and out. I'm done here.

Zenos, I appreciate your help, and got the add-on to work.

Just FYI, v5.1.2 IS the version I've downloaded, and that is the version that is directing me to the site page in German.

But if you are reading "more" in Thunderbird's Tools|Add-ons then you have already installed it.

The "more" page is clearly written by the original author. It links to amo so is clearly obsolete, since we are now getting this add-on from paolo kaosmos's website.

Kaosmos has a long-standing and well-respected site. Most of his add-ons are NOT made available through amo for reasons I don't fully understand, but I gather there is some cumbersome bureaucracy involved which kaosmos chooses not to become involved with.

In this case, he has done us all a favour by recovering an abandoned add-on and has hosted it on his own site. The "more"page is obsolete, as is the link on it back to the original author's version. It all goes to show the almost total lack of maintenance of the amo site.

Please, just use the damn' add-on.

Select some messages. Right-click. Select "Crawl selected emails for email addresses".

Hint for using Thunderbird effectively; if in doubt, right-click.

Thanks for the help and the right-click tip!