Since there is no version of Thunderbird that runs on Android devices your phone operation is not supported in this forum. That being said, if you want to manage your email from multiple devices you need to use IMAP email and not POP. If your provider does not have IMAP available then you need to tell your devices to leave the messages on the server so all devices can download them. Then you must delete and manage messages on all devices and the server.

I know there is no app for thunderbird I have set it up on my phone using the email app to add new accounts. When I check my email on my phone the new messages show on my phone but when I get home and use my PC the emails that are on my phone do not show on my PC in thunderbird and viceversa

What type of mail account do you have in Thunderbird? Is it a POP mail account?

Airmail's advice is correct.

Pop mail accounts look at Inbox on server and download anything on server that has not previously been downloaded to the Thunderbird pop mail account. It is normal for POP mail accounts to download and delete the copy off the server. So, it is also a good idea to backup emails. This means that if you then look at server either via webmail or another device eg: your phone, then that email will not be visible because it is not there.

To force POP mail accounts to download AND leave a copy on the server, you need to check this setting: 'Tools' > 'Account Settings' > 'Server Settings' for pop mail account or 'Menu icon' > 'Options' > 'Account Settings' > 'Server Settings'

• Select : 'Leave messages on server'
• Click on OK

This should resolve the issue in Thunderbird.

re: Phone It sounds like you have an app that is also POP. So it is doing the same thing - downloading and deleting off server. You need to search the settings on your phone app and select to leave a copy on server.

The only other option is to see if IMAP is available. This information should be located in your webmail account accessed via a browser. Currently, you are using POP mail forwarding. If IMAP forwarding is available, you could select that option. If you do this, then in Thunderbird (and on phone), you will need to create another exisitng mail account - an IMAP mail account for that email address; you canot simply alter the POP mail account. File > New > exisitng mail account. or Menu Icon > New Message > Exsitng Mail account

IMAP mail account settings are different to POP, the Username and Password will be the same, but they use a different port and probably a different server name. But as we (the forum) do not know what server you use, we cannot advise what the settings would be. Thunderbird does keep a large database of server names and attempts to locate the configuration when creating a new exisitng imap mail account.

Then you could put the POP mail account emails into 'Local Folders' or back on the server, before deleting/removing the pop mail account.

IMAP mail accounts see a remote view of the emails on the server. You subscribe to see folders. You can also synchronise folders to get a copy into Thunderbird which is useful for offline viewing. Anything you delete either via webmail, Thunderird or phone will delete off server and folders will synchronise to show what is on server.