If you use Apple’s iCloud email and use an iPhone/iPad as well as Outlook then you will find sent messages end up in different folders.
The iPad and iPhone will have 2 sent folders:
- Sent Items
Outlook will also have 2 sent folders:
- Sent items
- Sent messages
If you send an email from your iPhone/iPad it will go into the Sent folder but in Outlook it will appear in the Sent Messages folder.
If you send an email from Outlook it will go into the Sent Items folder and will also appear in the Sent Items on your iPhone/iPad.