How to Connect Mailbux to Thunderbird

Connect Mailbux to Mozilla Thunderbird

Thunderbird is a free, open-source email client that works great with Mailbux. This guide walks through adding your Mailbux account using IMAP and SMTP.

Note: IMAP/POP3 sign-in needs a paid plan; Free uses webmail, the Mailbux apps (JMAP) and SMTP.

What You Need Before Starting

• Mozilla Thunderbird installed (download here)
• A Mailbux — Free business email hosting on your own domain. Sign up now with at least one custom domain email address
• Your full Mailbux email address (e.g. [email protected])
• Your Mailbux account password

Server Settings

Setting	Incoming (IMAP)	Outgoing (SMTP)
Server	my.mailbux.com	my.mailbux.com
Port	993	587
Connection Security	SSL/TLS	STARTTLS
Authentication	Normal password	Normal password
Username	Full email address	Full email address

Step-by-Step Setup

1. Open Thunderbird. If this is your first account, the account setup wizard opens automatically. Otherwise, go to File > New > Existing Mail Account.
2. Enter your name, full email address, and password. Click Continue.
3. Thunderbird will try to auto-detect settings. If it finds incorrect settings or fails, click Manual config.
4. Set the incoming server:
   • Protocol: IMAP
   • Server hostname: my.mailbux.com
   • Port: 993
   • Connection security: SSL/TLS
   • Authentication method: Normal password
   • Username: your full email address
5. Set the outgoing server:
   • Server hostname: my.mailbux.com
   • Port: 587
   • Connection security: STARTTLS
   • Authentication method: Normal password
   • Username: your full email address
6. Click Re-test to verify the settings, then click Done.
7. Enter your password when prompted and click Sign in.

Troubleshooting

• Auto-detect finds wrong settings: Always click Manual config and enter the settings from the table above.
• Login failed: Make sure your username is the full email address (e.g. [email protected]), not just john.
• Cannot send email: Confirm you are using port 587 with STARTTLS for outgoing mail. If your network blocks 587, use 465 with SSL/TLS instead.
• Certificate warning: If you see a certificate error, confirm the server hostname is exactly my.mailbux.com.

Verify Your Setup

• SMTP Test — test that your outgoing mail server responds correctly
• MX Lookup — confirm your domain MX record points to my.mailbux.com
• Blacklist Check — check your sending IP reputation