The Manual Method involved to fix cannot send email messages in Thunderbird are: Method 1: SMTP Settings needs to be checked Thanks.” Manual Method to Fix Sending Messages Failed in Thunderbird As I have some important messages that has to be sent. “Hi! Recently I am unable to send messages from Thunderbird is because of some clash with some program like anti-virus or some other reason. Could someone tell me the way out as I will be grateful. I am unable to understand why such a problem is occurring. But recently while using Thunderbird I am unable to send messages. “Hello! I have been using Thunderbird for a very long time but I have never faced problem with it. We will understand the topic with the help of query: While using Thunderbird a user is bound to face error which can be of many type one of them is cannot send messages in Thunderbird.
The reasons are running of anti-virus program, Thunderbird is in offline mode etc. This could occur because of various reasons. unable to send mail messages in Mozilla Thunderbird. But there are times when there is an error i.e. It is developed by Mozilla for sending and receiving emails.
Thunderbird is a desktop-based email application that contains multiple features that are used professionally and personally by users all over the world.