Hello, first time asking for help, so I hope that I can be clear - I am using Thunderbird to access my Telus.net email, 78.6.0 on Windows 10 Pro, fibre optic internet. Telus has switched their mail system to one based on gmail, or gsuite. The changeover occurred during the late summer / fall for me. The server involved is imap.gmail.com, as per the "settings" in TB. I can send pictures (.JPG files) by dragging them to the compose window. They are sent, and also the message is placed into the "sent" folder, in about 3 seconds. The 3 pictures, in this instance, total about 900 kb in all. Perfect. The problem - when , I select the same 3 pictures in their folder on the computer and use the windows ">send to > mail recipient" context menu option, the TB compose window dutifully pops up, attachments listed at the top right in the box, but clicking "send" brings up the green progress bar which immediately fills in fully, and is followed in about 6 or 8 seconds by the message that the connection to the server has timed out. The message is not sent, with the same recipient and subject line as in the successful instance above. At this point and after searching for other online help, I found no results. I did change, in the TB config, the mailnews.tcptimeout number from the original 300 to 2000, but is didn't make any difference. I really wonder if it is a) a Windows issue, b) a TB issue, or c) a gmail issue. The only virus protection on board is Windows Defender and the Windows firewall. Thanks, Alan in BC