Thunderbird

Why an email program when webmail already works

A company quickly ends up with three or four addresses. The company's own address, maybe one on the domain you bought, and then everyone's private ones that get used sometimes anyway. Keeping track of them in separate browser tabs works until someone misses a customer email because the tab sat minimized for three days.

Thunderbird gathers all the addresses in one window. You see everything that has come in in a shared inbox, you reply from the right sender without switching accounts, and you keep the messages on your computer even when the internet is down. Calendar and contacts are in the same program.

There is a less obvious gain too: if the company switches email provider or closes a Gmail account, the correspondence stays with you, not just with Google.

What you need

• A computer with Windows or Linux. The program is also available for macOS.
• The email address and password for the account you want to connect.
• Twenty minutes for the first account, five for each one after that.

If you have two-step verification on the account, which you should, you may need an app-specific password with some providers. More about that further down.

Windows

1. Go to thunderbird.net. The page detects that you are on Windows and offers the right file.
2. Run the installation file and click through. The default choices are fine.
3. When asked whether Thunderbird should be the default program for email: answer yes if you want a clicked email link on a web page to open here.
4. Start the program. The first thing you meet is the box for adding an account.

Thunderbird updates itself in the background and tells you when a restart is needed. Let it. An email program is one of the programs that most often encounters something malicious, and old versions are not the place to save time.

Linux Mint

On Linux Mint, Thunderbird is preinstalled. If you still need to install it:

sudo apt install thunderbird

What you get is a real deb package that Linux Mint builds itself, currently version 153.2.0esr in Mint 22.3. ESR stands for extended support release, meaning the edition that receives security fixes for a long time without features being swapped out under your feet. For a program that just needs to work, that is the right choice.

On Ubuntu, it is not the same thing. If you type the same command there, you get a small intermediate package that installs the snap version instead. The program works, but it starts more slowly and does not always reach folders outside your home folder, which you notice when you attach a file. That is one of the concrete differences between Mint and Ubuntu, and Mint has made a deliberate choice here.

If you want the Flatpak version instead, for example because you already run everything else that way:

flatpak install flathub org.mozilla.Thunderbird

That installs the regular release track, not ESR. If you want the ESR track on Flatpak, the package is now called org.mozilla.thunderbird_esr. Do not mix several installation methods: run one of them, not several, otherwise you end up with programs pointing at different sets of mail.

Connect the first account

Enter your name, email address and password. Click next and let Thunderbird find the settings on its own. For Gmail, Outlook, Hotmail, iCloud and most Swedish providers, it finds the right ones in a few seconds.

Then comes the question that matters most, and it is easy to click past:

IMAP or POP3.

IMAP keeps the computer and the server in sync. If you read a message in Thunderbird, it is read on your phone too. If you delete it on the computer, it is deleted everywhere. The messages stay on the server.

POP3 downloads the messages to the computer. In the default mode, Thunderbird checks the box to leave the messages on the server for fourteen days, but if you change it to delete them right away, or let the time run out, the messages are gone from webmail and exist only on the computer that downloaded them.

Choose IMAP. That is the right answer in almost every situation, and especially when several people in the company need to reach the same address. POP3 remains for old special cases and for anyone who deliberately wants to move everything home from a server that is being shut down.

For Gmail and Microsoft accounts, a login window from the provider opens instead of the password being typed into Thunderbird. That is OAuth, and that is how it should look. Approve the permissions and you are done.

With providers that do not have OAuth, and where you use two-step verification, you need an app-specific password. You create it in the provider's security settings and paste it into Thunderbird instead of your regular one. Your regular password simply does not work there, and the error message usually does not explain why.

Multiple accounts, and replying from the right address

Add the next account via Account Settings, Account Actions, Add Mail Account. The same procedure.

When you have two or more, one thing becomes important: check the sender before you press send. Thunderbird selects the account the email arrived at, which is usually correct, but not always when you write a new message. A quote reply that goes out from someone's private address looks careless. The sender is shown in a drop-down menu at the top of the compose window.

The menu bar is hidden by default. Click the app menu button (the three lines at the top right) and go to Folders, Unified Folders, or press Alt to temporarily show the classic menu bar with View. Then you see an inbox with everything in it, and can still expand it to see which account each message belongs to.

Four things to do right away

1. Write a signature. Name, role, company name, phone. No quote, no slogan. It is added under Account settings for each account, and it should look the same for everyone in the company so that the emails are consistent.
2. Make one folder per customer or project. Right-click on the account, New folder. Drag in the emails that belong there. An inbox with four hundred emails is not an archive, it is a pile.
3. Set up a filter. Open the app menu button (the three lines at the top right) and go to Message filters, or press Alt to show the classic menu bar with Tools. Let everything from the company's own address land in its own folder right away, so the important mailings do not drown among newsletters.
4. Add the calendar. The calendar is built in. Create a local calendar for the company's meetings and deadlines, or connect an existing one via a CalDAV address if you have one. A Google calendar is connected built in via CalDAV, you log in with the Google account and approve the permissions. No extra add-on is needed.

Sharing one address in the company

If you have a shared address, for example info on your domain, several people can connect it to their own Thunderbird with IMAP. Everyone sees the same messages, and if someone reads a message it shows as read for the others.

It works technically. What goes wrong is the way of working: two people answer the same customer the same evening, with different information. Decide on a simple rule in the company before it happens, for example that whoever answers moves the message to a folder called Answered. It is low tech and it holds up.

The password for the shared address belongs in the company's password manager, not in a group chat. The guide about Bitwarden here on the site goes through that.

When something goes wrong

Thunderbird does not find the settings automatically. Enter them by hand. You need the server address, port and encryption method for both incoming and outgoing mail, and those details are in your provider's help pages. The most common setup is IMAP on port 993 with SSL, and SMTP on port 465 with SSL or 587 with STARTTLS. Do not guess; look up your provider's own information.

You can receive but not send. Then the outgoing server, SMTP, is not set up correctly. Check it separately under Account settings, Outgoing server. Many providers require you to log in even to send.

The password is rejected even though it is correct. Two-step verification is on and you need an app-specific password. See the paragraph above.

The program becomes slow after six months. Right-click a folder, Properties, Compact. Deleted messages remain as space in the folder file until this is done.

Images do not show in messages. That is intentional. Thunderbird blocks remote content, because an embedded image can reveal that you opened the message. Click the bar at the top of the message to show them when the sender is someone you know.

A message has disappeared. Check the junk folder and the search function before you assume the worst. Thunderbird has its own junk filter that learns from what you mark, and at first it sometimes marks the wrong things.

The license

Thunderbird is under MPL-2.0 and is run by MZLA Technologies Corporation, a subsidiary of the Mozilla Foundation. It is funded by donations, not by ads, which is unusual for a program that reads your email. You may use it in the company, install it on all the company's computers and keep using it afterwards.

There is also an app for Android. You connect it the same way, with the same IMAP settings.

Do you need help getting the company's email and domain in order? Get in touch.