Outlook for Mac EWS compatibility fixes for gromox/grommunio

We worked on improving Outlook for Mac compatibility with gromox/grommunio over EWS. Initial symptoms: - Outlook for Mac synchronization blocked on Drafts and Inbox - message drafts not correctly updated - recipients not persisted reliably - messages sometimes remained in Drafts after send - Sent Items copy missing or inconsistent - existing mailboxes had folder layout issues compared with newly created accounts Main fixes implemented: 1. SQLite mailbox store compatibility - aligned existing mailbox folders with the expected EWS distinguished folders - ensured missing special folders such as Archive, Conversation History and Recipient Cache exist with expected folder IDs/properties - verified folder_properties and folder IDs against a newly created working mailbox 2. EWS distinguished folder mapping - added/corrected mapping for EWS distinguished folders: - archive - archivemsgfolderroot - conversationhistory - quickcontacts - recipientcache - sentitems - ensured Outlook for Mac can resolve expected folder names 3. Recipient handling in UpdateItem - Outlook for Mac sends recipients through UpdateItem flows - implemented explicit handling of: - ToRecipients - CcRecipients - BccRecipients - ensured recipients are persisted before sending - avoided destructive recipient-table rewrites 4. Message send behavior - fixed SendOnly / SendAndSaveCopy behavior - ensured messages are submitted - ensured sent messages are moved/copied to Sent Items - ensured messages disappear from Drafts after successful send Validation: - Outlook for Mac can create, edit and send messages - To and Cc recipients are visible in Sent Items - messages arrive externally, tested with Gmail and Free - sent messages are present in Sent Items - messages no longer remain stuck in Drafts - tested on existing and newly created mailboxes