Not supported in Gmail
The following Microsoft® Outlook® features aren't available in Gmail and therefore aren't available from the Gmail interface. Except where noted, however, these features are still available in your G Suite profile in Outlook, when using G Suite Sync for Microsoft Outlook (GSSMO).
- Posts in folders: You can store posts in your Outlook mail folders and they remain available in Outlook. But they don't appear in Gmail.
- Message flag follow-up dates or reminders: Flagged messages in Outlook are starred in Gmail. But follow-up dates or reminders associated with a flag don't appear in Gmail (since Google stars don't have these features).
- Category assignments: Gmail doesn't have a feature equivalent to Outlook categories, so any categories you assign to a message in Outlook don't appear in Gmail.
- Multiple signatures: Unlike in Outlook, you can create only one signature in Gmail.
- Public folders: G Suite doesn't support public folders, either in Outlook or in Gmail.
- Importance levels: You can't mark messages as Important or Low Priority in Gmail, as you can in Outlook.
- Delivery receipts: When sending a message from Gmail, you can't request an automatic response when the message is delivered.
- Forward or Reply arrows: Gmail doesn't mark messages you've forwarded or replied to, with a small arrow icon, like Outlook does.
- Editing messages in your Inbox: You can use Outlook to edit the body or subject of a mail message you've already received (or sent). However, those edits don't appear in Gmail.