[Pollard]

https://www.thunderbird.net/en-US/

Install thunderbird and download all your emails to your computer. It’s not going to do so automatically. By default, it only downloads the headers and then you you open an email it will download it to a temporary file. You’ll have to go into account settings and set it to download everything.

OR

Thunderbird sets up a Local Folder on install. You could highlight all emails in the gmail account and drag them over to the Local folder.

1st option would be best though.

Then, get prontomail.

[HeadOn]

Thanks.

[ELS]

Then, get prontomail.

Do you mean, prontomail. or Protonmail?