I tried the manual method you suggested from the above mentioned link, But I can’t proceed that completely due to some technical error. Also, I read about one third-party solution from that same article. If you can, please give some more idea about that tool.
I can explain about that third party tool mentioned in the article, because once I used that tool. Actually manual methods are cost-free so first I am suggested that to you first. SysTools Zoho Backup tool is specially designed to export Zoho email in Thunderbird MBOX file format. Also, it has the proficiency to access in PST, EML, and MSG file formats too. After convert Zoho mail to format with the help of this utility you can import that file to Thunderbird.
I am really thankful to you, because you help me to reach to the perfect solution. I have tried the demo version of SysTools Zoho Backup tool so, I realized it can provide the result I wanted. So, now I decided to purchase it’s full version.