Send
Inbox > Write
Options > Delivery Format > Plain Text Only
Compose
From the main menubar, Edit > Account Settings
Go to "Composition & Addressing"
Un-check "Compose messages in HTML format"
Inbox > Write
Options > Delivery Format > Plain Text Only
From the main menubar, Edit > Account Settings
Go to "Composition & Addressing"
Un-check "Compose messages in HTML format"