Connect your mailbox in Thunder­bird

Before you start

Set up incoming IMAP and outgoing SMTP using the concrete settings below. They come from SGCloudApp’s previous Thunderbird guide; any different settings issued for your account take precedence. Your mailbox must already exist before you add it to Thunderbird.

This guide covers Account Hub in Thunderbird 150 and later, with current interface wording checked against Thunderbird Desktop 158.0.1, released October 20, 2026. Versions before 150 used the legacy Account Setup by default; those steps are listed separately below.

yourdomain.com and johndoe@yourdomain.com are placeholders. Replace them with your domain and full mailbox address. Use mail.yourdomain.com only when it is configured for your service and its certificate is valid for that exact hostname. Otherwise, use the server hostname your administrator confirms.

Your IMAP and SMTP settings

Settings from the previous SGCloudApp Thunderbird guide. Your issued account settings take precedence.

The original guide explicitly pairs IMAP 143 and SMTP 587 with STARTTLS and Normal password. Select all of those values; changing a port does not replace selecting encryption.

Normal password must be used over the selected encrypted connection. Never choose “None” for connection security. Do not switch this account to OAuth2 unless your administrator has explicitly issued a different authentication configuration.

1. Open Account Hub

1. Install or update Thunderbird from the official Thunderbird website.
2. Open Thunderbird. On a first run, Account Hub opens into email setup.
3. If you already use Thunderbird, open the application menu, then choose Add Account → Email. Some older versions call the menu New Account instead.
4. Enter your Full name as you want recipients to see it and your Email address, for example johndoe@yourdomain.com. Select Continue to look up the configuration.

This connects an existing mailbox; it does not create a new SGCloudApp mailbox. Enter passwords only in Thunderbird’s trusted account flow, not in this guide or the support enquiry form.

2. Review discovery or choose manual setup

If Thunderbird finds settings, compare the incoming and outgoing values with the table and your issued account settings. Automatic discovery does not establish that a proposed hostname or authentication method is right for your mailbox.

If discovered settings need correction, select Edit configuration on the result screen. If discovery fails, return to the email-address screen and select Manual configuration below the email-address field. You can also use that control to begin manual setup directly.

When asked to choose an account type, select IMAP and then Set up account. Current Account Hub can show an IMAP Settings form with both incoming and outgoing server sections.

3. Enter both server con­fig­ura­tions

1. Under Incoming server, enter mail.yourdomain.com in Hostname, your full mailbox address in Username, Normal password in Authentication method, STARTTLS in Connection security, and 143 in Port.
2. Under Outgoing server, enter the same confirmed hostname, Normal password, STARTTLS, and 587. The SMTP username must also be your full mailbox address. If Same username as incoming server is shown, select it only when the incoming username is the correct full mailbox address.
3. Select Connect in the current combined IMAP form. Thunderbird checks the configuration as part of this action. If it proposes updated values, review them against your issued settings before proceeding; do not accept a change to an unencrypted connection.

Different Account Hub layouts: Some versions or configurations show Incoming server settings and Outgoing server settings on separate screens instead. Enter the same values on each screen, use Continue to move forward, and select Test on the outgoing screen where offered. Resolve errors before continuing. This is an Account Hub variation, not the legacy Account Setup described below.

4. Enter credentials and finish

1. When Thunderbird asks for your Password, enter the password for this mailbox. Choose Remember password only if storing it on that device is appropriate for you, then select Continue. Do not enter a hosting-control-panel password in place of the mailbox password.
2. If Thunderbird offers connected calendars or address books, select only the services you want and are authorized to use, or skip that optional step.
3. After the account-success screen appears, select Finish.

If authentication fails, recheck the full-address username and mailbox password. If any certificate, server-identity or insecure-connection warning appears, stop and resolve it rather than creating an exception.

5. Check both sending and receiving

1. Open the account’s Inbox and let Thunderbird retrieve messages. An empty Inbox alone is not evidence of a setup failure.
2. Send a non-sensitive message to another mailbox you control.
3. Reply from that mailbox and confirm that the first mailbox receives the reply.

Incoming IMAP and outgoing SMTP are separate connections. A successful receive check does not confirm that sending works.

If receiving fails

Open Account Settings, select your mailbox and open Server Settings. Check the incoming hostname, port 143, STARTTLS, Normal password and full mailbox username against your issued settings. Changing an existing account from POP3 to IMAP is not a simple port change; ask for migration guidance rather than overwriting a working account’s protocol.

If sending fails

Open Account Settings → Outgoing Server (SMTP) and edit the SMTP entry for this mailbox. Confirm the hostname, port 587, STARTTLS, Normal password and full-address username. Then select the mailbox’s main account settings and make sure its Outgoing Server (SMTP) selection points to that entry. With multiple accounts, an otherwise correct SMTP entry can be assigned to the wrong mailbox.

If you see a certificate warning

Do not select Trust, add a security exception, or disable encryption. The certificate must be trusted, in date and valid for the exact hostname entered. Merely seeing “sgcloudapp.net” in it does not validate mail.yourdomain.com.

Check the hostname and your device’s date and time. If the warning remains, stop and ask your administrator for a server hostname covered by a valid certificate or for the certificate to be fixed. Do not guess a srvX hostname.

Legacy Account Setup — versions before 150

Before Thunderbird 150, the legacy Account Setup was the default. Use this section only if your installation displays that older setup interface, not as the required workflow for Thunderbird 158.

1. Open Account Settings → Account Actions → Add Mail Account. In some older desktop versions, Account Settings is under Tools.
2. Enter your name, full mailbox address and mailbox password, then select Continue.
3. Choose the manual setup control. The old SGCloudApp guide calls it Manual Config; some older dialogs label the control Manual Configuration. Enter the IMAP and SMTP values in the table above.
4. Use Re-test where that older dialog offers it, correct any errors, and complete the dialog using its final account-creation control. The original SGCloudApp screenshots used Done; Done and Re-test are not mandatory current Account Hub labels.

View all email settings and webmail guidance

Thunder­bird references

Current setup labels were checked against Thunderbird 158.0.1 release source, not a live mailbox login.

• Mozilla: Account Hub for Thunderbird Desktop
• Mozilla: Manual Account Configuration
• Thunderbird 158.0.1 release notes