Can’t paste into body of email.
A few things to check if paste isn’t working in the composer: (1) Make sure you’ve clicked inside the message body first to focus it — pasting into the To/CC fields has different behavior. (2) Try Ctrl+Shift+V (or Cmd+Shift+V on Mac) to paste as plain text if normal paste isn’t working. (3) If you’re on Linux/Wayland, there can be clipboard issues with certain setups — try copying the link again and pasting immediately. (4) Check that rich text mode is enabled in Preferences > Composing if you’re trying to paste formatted content. If none of these help, let us know your OS and Mailspring version.