Unfortunately , we have no access to your wifi setup. I suggest you contact your ISP for assistance in that.

Everything is good at my ISP is it related to thunderbird. Can you please check.

OK, you posted it as a wifi problem, but if you post a screen shot of your server setup and your SMTP server setup, maybe some ideas will surface. I am referring to the panes that show server, port, authentication and email.

Can we get on a call and resolve this as my work is affected due to this

The forum is our only support. If you will post some specifics, we may be able to help.