How to solve Mozilla Thunderbird SMTP Server Error?

Admin | Featured How to's Technology | 2 minutes read | Last updated on February 8th, 2023,

Exact Error

In this technical error of the Mozilla Thunderbird application, users cannot send messages or reply to the received emails. You may get an error message that is “Try Again” when you send a message. This error is related to the outgoing SMTP server and you can resolve this problem by following some steps.

Reason for Error

All message delivery processes are done by Mozilla Thunderbird SMTP Server and if you are facing an error in sending messages, it directly connected to the SMTP server. This may occur when the server blocked port 25 by ISP (Internet Service Provider). You can receive this error with multiple statements.

Procedure to Resolve Thunderbird SMTP Error

#1. Outgoing Mails Settings

  • Start your Mozilla Thunderbird application and then go with the Tools option.
  • Choose the Accounting Settings from the menu.
  • Hit on the Outgoing Server (SMTP) to check the configured settings of the SMTP server.
  • After this process, you need to check the updated SMTP setting in this way:
  • Open Thunderbird application and by the use of the Tools option choose the Account Settings option. Now, check the relevancy of the entered SMTP server address.

#2. Blocked Services Check-up

Several times the Mozilla Thunderbird SMTP error has occurred when the antivirus or firewall applications block the delivery of Thunderbird emails. So it is necessary to check it out:

  • Firstly, you need to send mail without disabling the antivirus or firewall system. If you have trouble with this process again, then you are required to follow the message sending process again after disabling the antivirus software.
  • Sometimes, ISPs blocks outgoing mails by port 25. So, you need to change this port number as per the service provider’s advice.

#3. Removal of SMTP Password

This error may also remove by deleting and then reconfigured the Thunderbird email application:

  • You need to update the Mozilla Thunderbird to the latest edition.
  • Then, you are required to send any email again to check whether this error is resolved or not.
  • If you still experience this error then move towards the Tools and after that Options.
  • Select the Security option and then hit on the Password tab.
  • Delete the SMTP password and reconfigure the account again.
  • Now, send the email again to check the processing of send messages from Mozilla Thunderbird.


This error can occur with any Mozilla Thunderbird account at any time. So we have discussed the common way to resolve the error that is “Thunderbird SMTP Server Error”. You can follow these methods to get your Thunderbird account with accurate processing.