To install the crawler add-on, you first have to change a preference:

https://support.mozilla.org/en-US/questions/1264224#answer-1235926

That discussion includes comments about usability.

I made extensions.strictCompatibility to false. I installed EMAIL ADDRESS COLLECTOR, but the addresses in the inbox were not added to the address book. My TB version is 60.8. i tried installing address crawler but it isnt compatible with TB version 60.8 hence could not be installed,

The crawler add-on is installed and working here in TB 60.9.

https://freeshell.de//~kaosmos/index-en.html#eac

Make sure extensions.strictCompatibility is false. When you get the add-on installed, look carefully at the settings in the window that appears when you right-click a folder, 'Crawl folder for email addresses' (see picture).

Thank you. I am not able to install the crawler. I get the error message that it is not compatible with TB. Please see attachment.

I need to get all addresses in gmail to be imported in TB. I installed Gcontactsync but it is not working, may be I dont know how to use it. If I right click any folder I dont see any option for GContactsync. The notes for this addon say that I have to enable Javascript and cookies. Both are enabled but this addon isnt working. I have installed Gcontactsync version 2.1.13 since my TB version is 60.8.0.

The error shows you are trying to install Email Address Crawler 3. This is not the add-on I suggested in my last reply, EAC 5.1.2.

To import Gmail contacts, see this post.

Thank you so much. The EAC 5.1.2 works very well. And the link for importing gmail contacts is very useful too.