Running iOS 18 beta on iPad 9th Gen. I have two email accounts set up in Mail - an iCloud account which is the default account in 'Settings>Apps>Mail>Default Account'. I also have a Gmail account - which gets most of my mailing list, digests and general 'junk' etc. I use the Mail app & the 'All inboxes' view to read my emails on my iPad. I want to send all new messages from my iCloud account but, despite it being the default, this does not happen. Whenever I start a new message, the sending account selected depends on the highlighted message in the left column. So, when I start a new email to my wife, if I happen to have a mailing list message selected from my Gmail account, the email gets sent from my Gmail address. Unfortunately I have more mail sent to my Gmail account than my iCloud so it is more likely that the non-default account is chosen. On macOS, the default sending address is honoured whatever email is selected. This is inconsistent behaviour between the two systems.