1) The cautious approach is that unless you do something about it, you should assume that your messages are saved on a server.

The default behaviour for POP is to download to the client then delete from the server, but there is a setting to override this and leave messages on the server. You need to be sure this feature is disabled, if your accounts use POP.

If you are using IMAP then by design it stores all your messages on the server. You will need to actively do something, such as moving messages to Local Folders, to avoid them languishing on the server.

2) If you encrypt a message and send it to me, I need to know how to decrypt it. If I can read it without this knowledge then it isn't actually encrypted, is it?

The commonly encountered systems used in email employ pairs of keys. You publish your public key for your correspondents to use to encrypt messages sent to you, and you use your private key to decrypt them. To send encrypted messages to others, you need their public key to encrypt, and they use their own private keys to decrypt. Both parties need to buy into encryption and get set up to create, use and publish keys. Publishing your public key is easy; you can attach it to outgoing messages, or you can place it on a public keyserver.

The alternative is to write what you have to say as a standalone document or documents, zip it/them with a password, attach the zipped file(s) to an email and somehow convey to your correspondent the password. Emailing it to them rather defeats the purpose, if you feel you cannot trust email.

I am told that if your email provider offers SSL or TLS then your message contents are encrypted. I am not convinced, as some email providers do not offer these encryption services, so for at least some part of the journey between sender and recipient the message might be sent in clear text, i.e. unencrypted.

Any mail clients worth using natively support S/MIME. Thunderbird does. The pain is in getting and installing your key pair. There are providers who will charge you for keys. Comodo do one for free but they deliver it to your browser and you have to export it and re-import it into Thunderbird. This system has the greatest chance of "just working" with other email clients.

Thunderbird can use an alternative, GPG, usually via the Enigmail add-on, but you will find few other mail clients that support this system. Creating and installing keys is easier, but perhaps the creation of them is too easy such that they don't have terribly good credibility.

I have used zipped files with passwords. On one occasion I lost/forgot the password and I contacted the zip utility's supplier for advice on "cracking" it. I expected to have to pay them to do this for me, but they just pointed me to shareware crackers which told me enough to make an informed guess at the password, for free and within seconds. Encryption standards have improved since then, but do check for yourself how secure a password-protected zip file is. Note that some programs such as MS Word also offer password locking of documents, but you need to be sure your correspondents are equipped with the tools they need to be able to read your documents.

THank you for the response.

Can you give me instructions on how to set up my gmail and outlook in Thunderbird so it does not keep a copy on their fmail and outlook's server? Or thunderbird's server?

Thank you

Gal

Do you use POP, or IMAP?

Tools|Account Settings, select the account, go to Server Settings and read the "Server type" at the top.

POP gives you the most straightforward solution; just go to Tools|Account Settings, select the account, go to Server Settings and clear the checkbox named "Leave messages on server".

With IMAP, the easiest solution, if you can't switch to POP, is to just move messages on receipt to Local Folders. Be aware that the email provider may already by filtering messages to Spam, Important and suchlike. You can automate the movement of messages from Inbox to Local Folders by use of a Message Filter, found under Tools in the menu.

1. I opened my Outlook email in Thunderbird... It says IMAP. I could not change it... So I moved folder to LOCAL FOLDER... Does that mean it stays in my computer? Where is it?

2. So this way, you are saying the emails do not stay in the OUTLOOK SERVERS???

3, Does Thunderbird have an APP for Android to read the emails? I DID NOT FIND!

4. And Can I use Tutanota emails with Thunderbird?

1) No you don't change an existing account from POP to IMAP or vice versa. You add it as a new account in Thunderbird, taking care to choose the type you want. By default, Thunderbird will select IMAP and you may have to override this and set up for POP by hand. I should warn you that MS email has been changing to offer and advocate IMAP and discourage POP.

2) Moving messages in Thunderbird from the Outlook account to another account will cause the server to delete them. I suggest Local Folders because that is guaranteed to be using local storage.

3) No, Thunderbird is designed and compiled for Windows, OSX and Linux. There are no versions of it for IOS or Android. On your tablet or phone you just use their own email apps.

4) Tutanota would appear to be unsuitable for an email client. They offer "end-to-end encryption" which means they will offer the end-user client as part of the package. Tutanota appear not to be interested in email clients; all their support seems to be aimed at web browsers. Thunderbird works with SMTP, and POP or IMAP and none of those seem to be on offer, nor do they mention any plugin for Thunderbird to support their encryption and decryption. Email clients such as Thunderbird are generally used by people who dislike webmail, but that seems to be exactly where Tutanota want to work.

Regarding answer #3 from above:

If I use OUtlook and Gmail from their own APP in my phone... so it will cause the emails to stayon the OUtlook and Gmail servers - which means there is no security! So what would be the point of that?

Also, if I use OUtlook and Gmail in THUNDERBIRD and then I open OUtlook and Gmail - won't I see all my emails there as well?

I guess what I am trying to ask is: I would like to use OUtlook and Gmail in Thunderbird but without having them go through OUtlook and Gmail or stay on their servers?

thank you again

You can delete the messages via your phone/tablet app.

Why would you want to accumulate messages on a device with limited and precious memory? Phones and tablets use a variant of IMAP by design, because the designers acknowledge that few users would want to fill their portable device with email.

Whatever you use, your messages sit on the server until you download and delete them. They just sit there for longer if you use a mobile device, assuming that at some point you'll use Thunderbird to download and delete them permanently. (But be careful; gmail don't like deleting and tend to hide "deleted" messages inside the All Mail folder.)

I fear you are labouring under the misapprehension that Thunderbird operates a server for you. I am afraid this is not the case. If you really don't like Outlook or Gmail then find another provider. But wherever or however you do your email, messages will sit on a server UNTIL you deal with them.