How to Add an Email Account in Mozilla Thunderbird

This guide shows you how to add a Noiz mailbox to Mozilla Thunderbird, the free desktop email client for Windows, macOS and Linux, so that you can send and receive mail for your own domain from your computer. You will see both ways to set an account up: the automatic path, where Thunderbird tries to work the settings out for you, and the manual path, where you type the exact Noiz server settings in yourself. The manual path matters here, because a mailbox on a custom domain such as yourdomain.com very often does not autoconfigure, so knowing the correct settings saves a lot of guesswork. This article is for Noiz email clients whose mailbox lives on the Noiz mail platform.

Along the way you will also decide between IMAP and POP, the two protocols Thunderbird can use to fetch your mail. For almost everyone on Noiz hosting the answer is IMAP, and the reasoning is explained below so the choice is yours to make with confidence.

Last reviewed: 27 July 2026, against Mozilla Thunderbird 140 (latest stable Release and ESR). This guide is written for Noiz hosting and is kept current against Thunderbird. It complements, and does not replace, the official Thunderbird documentation linked below. Thunderbird updates frequently and the wording of buttons or the layout of the Account Setup screen can vary slightly between the monthly Release and the ESR (Extended Support Release), so if a screen differs from what you see here, the field names and values remain the same even when their arrangement moves.

Official Documentation Reference

• Thunderbird Support (Mozilla): the official support hub for Thunderbird, kept current with the latest release.
• Automatic Account Configuration: how Thunderbird tries to discover mail settings for you, and why it sometimes cannot.
• Manual Account Configuration: the reference for every field in the manual setup form, including protocol, ports and connection security.

Prerequisites

• The mailbox already exists on the Noiz mail server. If you have not created it yet, do that first: see How to Create a Mailbox in Plesk. Thunderbird can only connect to a mailbox that has already been provisioned.
• You know the full email address, for example [email protected], and the password that was set when the mailbox was created. The username for Noiz mail is always the full email address, not just the part before the @.
• Thunderbird is installed on your computer. Download it from the official Thunderbird website and keep it up to date, so you get current security fixes and the modern setup screen described here.
• A working internet connection, and a domain whose mail is hosted at Noiz. If your domain was only recently pointed to Noiz, allow DNS changes time to take effect before the mail hostname will resolve.

IMAP or POP: Choose the Right Protocol

Before you add the account, decide how Thunderbird should collect your mail. The two options are not interchangeable, and switching later means removing and re-adding the account, so it is worth a moment now.

• IMAP keeps your mail on the Noiz server and mirrors it to Thunderbird. Folders, read and unread status, and every message stay in sync across all your devices. Read a message on your phone and it shows as read in Thunderbird; file it into a folder on your laptop and that folder appears everywhere. This is the right choice for almost everyone, and it is what Noiz recommends.
• POP (POP3) downloads your mail to one computer and, by default, removes it from the server. It suits a single device with no need for webmail or a second device, and it can help if you deliberately want mail stored only on your own machine. Its weakness is that your other devices and Noiz webmail will not see mail that a POP client has already pulled down.

The practical rule: if you check mail on more than one device, or ever use webmail, choose IMAP. Only choose POP if you have a specific reason to keep mail on a single computer. The rest of this guide uses IMAP as the example; the manual settings table also lists the POP values in case you need them.

The Noiz Mail Settings

These are the settings a Noiz mailbox uses. Wherever you see yourdomain.com, replace it with your own domain. Keep this table to hand: the manual setup in the next section is simply a matter of typing these values into the matching fields.

If you decide on POP instead of IMAP, the only change is the incoming server: use the same hostname mail.yourdomain.com with port 995 and SSL/TLS. The outgoing SMTP settings are identical either way.

Two points that trip people up on custom domains:

• The username is the whole address, including @yourdomain.com. A username of just you will fail authentication.
• Both incoming and outgoing use SSL/TLS on the encrypted ports (993, 465 and 995). Do not use the older unencrypted ports (143 for IMAP, 110 for POP, 25 or 587 without encryption); Noiz mail is secured throughout.

Open the Account Setup Screen

If this is the very first time you have opened Thunderbird, the Account Setup screen appears on its own and you can skip straight to the next section. Otherwise, open it manually:

1. Click the ☰ menu button (three horizontal lines) at the top right of the Thunderbird window.
2. Choose New, then Existing Mail Account…

The same screen is reachable from Account Settings: open the ☰ menu, choose Account Settings, then at the bottom of the left panel click Account Actions and Add Mail Account. Either route opens the Account Setup tab.

Enter Your Details

On the Account Setup tab, fill in the three fields at the top:

1. Your full name: the name you want recipients to see, for example Jane Smith.
2. Email address: your full Noiz email address, for example [email protected].
3. Password: the mailbox password. Leave Remember password ticked if you want Thunderbird to store it, so you are not prompted each time.

Path A: Try Automatic Setup First

Click Continue. Thunderbird now tries to discover the settings by checking its own provider database and by looking for a configuration file published at your domain. If it succeeds, it shows one or more Available configurations, usually offering both an IMAP and a POP3 option.

1. Select IMAP (already selected by default when offered).
2. Click Done.
3. Confirm the discovered values against the Noiz settings table above. In particular check that the hostname is mail.yourdomain.com and that the ports are 993 (incoming) and 465 (outgoing) on SSL/TLS.

Why automatic setup often does not work on a custom domain. Thunderbird's automatic discovery relies on either a known large provider or a small configuration file that the domain publishes for the purpose. Most custom domains hosted on a standard mail platform do not publish that file, so Thunderbird either finds nothing or guesses settings that then fail to connect. This is expected and is not a fault with your mailbox. When automatic setup fails, or offers settings that do not match the table above, switch to the manual path below. It is completely reliable because you supply the exact values yourself.

Path B: Configure Manually (Recommended for Custom Domains)

From the Account Setup tab, after entering your name, address and password, click Configure manually. This expands the full set of server fields. Enter the values exactly as follows.

Incoming Server

1. Protocol: choose IMAP (or POP3 if you deliberately chose POP earlier).
2. Hostname: mail.yourdomain.com
3. Port: 993 for IMAP (or 995 for POP3).
4. Connection security: SSL/TLS.
5. Authentication method: Normal password.
6. Username: your full email address, for example [email protected].

Outgoing Server (SMTP)

1. Hostname: mail.yourdomain.com
2. Port: 465
3. Connection security: SSL/TLS.
4. Authentication method: Normal password.
5. Username: your full email address, the same as the incoming username.

Test and Finish

1. Click Re-test. Thunderbird connects to the incoming and outgoing servers with the values you entered and confirms they work. A green message reports that the settings were verified.
2. Click Done. Thunderbird creates the account and begins downloading your folders and messages.
3. If a confirmation screen offers to link other services or set up encryption, you can safely click Finish now and revisit those later.

Your Noiz mailbox now appears in the folder list on the left. Send yourself a short test message and reply to it to confirm that both sending and receiving work end to end.

Troubleshooting

• Symptom: "Unable to log in at server" or repeated password prompts. The most common cause is a username that is not the full address. Open the ☰ menu > Account Settings, check Server Settings (incoming) and Outgoing Server (SMTP), and make sure both usernames are the complete [email protected]. Then confirm the password by signing in to Noiz webmail with the same details; if webmail also rejects the password, reset it where the mailbox was created.
• Symptom: Thunderbird cannot find the settings automatically. This is normal for a custom domain. Use Path B: Configure Manually above and type the Noiz settings in yourself.
• Symptom: a security or certificate warning about the mail host. Make sure Connection security is SSL/TLS on ports 993, 465 or 995, and that the hostname is spelled exactly mail.yourdomain.com. A warning that the certificate name does not match usually means the domain's mail is not yet fully live on Noiz, or DNS has not finished pointing to the mail server. If your domain has only recently moved to Noiz, wait for DNS to take effect and try again, or contact Noiz support for the correct hostname to use in the interim.
• Symptom: mail is received but will not send. This is an outgoing (SMTP) problem. Check that the SMTP server uses port 465, SSL/TLS, Normal password, and your full email address as the username. Some networks block outgoing mail ports; if sending fails only on a particular network, try another connection to confirm.
• Symptom: the incoming server host does not resolve. Confirm the domain's mail is hosted at Noiz and that DNS has propagated. Until then, mail.yourdomain.com may not point anywhere. Noiz support can confirm the status of your mail DNS.

If you work through the settings above and the account still will not connect, open a support ticket with the Noiz support team. Include the email address, whether the problem is with sending, receiving or both, and a screenshot of any error message Thunderbird shows. On Noiz managed plans the support team can verify the mailbox and its settings from the server side and point you to the exact value to correct.