Microsoft 365 via CLI for Microsoft 365

This skill uses the m365 CLI (CLI for Microsoft 365) to interact with Outlook email and calendar via the Microsoft Graph API. It works cross-platform (macOS, Linux, Windows).

Connection Check

Before doing anything, run these two commands in parallel:

m365 status --output json
m365 connection list --output json

If the active connection already has "authType": "secret", proceed to the task.

If the active connection has a different auth type (e.g. deviceCode), check connection list for an inactive connection with "authType": "secret". If one exists, activate it:

m365 connection use --name "<connection-name>"

Only if no secret connection exists at all, read ./setup.md (relative to this file) and follow the setup steps.

All commands that target a user's mailbox require --userName <upn> (built-in commands) or the user principal name in the Graph API URL. Ask the user for their UPN (e.g. user@company.com) if not known.

Important Notes

• ALWAYS confirm with the user before any write action (send email, create/delete event).
• The CLI has built-in commands for email but NOT for calendar events. Use m365 request with Graph API URLs for calendar operations.
• Use --output json for machine-readable output. Use --query (JMESPath) to filter fields.
• Every command supports -h / --help. Use m365 <command group> --help to discover commands.

Email

List messages

m365 outlook message list --folderName inbox --userName <upn> --output json

# With date range (endTime must be in the past)
m365 outlook message list --folderName inbox --userName <upn> \
  --startTime "2026-02-01T00:00:00Z" --endTime "2026-02-15T00:00:00Z" --output json

# Compact output with JMESPath
m365 outlook message list --folderName inbox --userName <upn> --output json \
  --query "[].{subject:subject,from:from.emailAddress.address,received:receivedDateTime,isRead:isRead}"

Folder names: inbox, drafts, sentitems, deleteditems, junkemail, archive. You can also use --folderId.

Read a specific message

m365 outlook message get --id <message-id> --userName <upn> --output json

Search emails (via Graph API)

The built-in message list does not support search. Use m365 request with $search or $filter:

# Full-text search (subject, body, sender, etc.)
m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/messages?\$search=%22keyword%22&\$select=subject,from,receivedDateTime&\$top=10" --method get --output json

# Filter by sender
m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/messages?\$filter=from/emailAddress/address eq 'someone@example.com'&\$select=subject,receivedDateTime&\$top=10" --method get --output json

Note: $search and $orderby cannot be combined. Results from $search are ranked by relevance.

List mail folders

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/mailFolders?\$select=displayName,id,totalItemCount,unreadItemCount" --method get --output json

Send email

# Plain text
m365 outlook mail send --subject "Subject" --to "recipient@example.com" \
  --sender "<upn>" --bodyContents "Message body" --output json

# HTML with multiple recipients
m365 outlook mail send --subject "Subject" --to "a@example.com,b@example.com" \
  --cc "c@example.com" --sender "<upn>" \
  --bodyContents "<p>HTML body</p>" --bodyContentType HTML --output json

# With attachment (max 3 MB per attachment)
m365 outlook mail send --subject "Subject" --to "recipient@example.com" \
  --sender "<upn>" --bodyContents "See attached." \
  --attachment "/path/to/file.pdf" --output json

# Send from shared mailbox
m365 outlook mail send --subject "Subject" --to "recipient@example.com" \
  --mailbox "shared@company.com" --sender "<upn>" \
  --bodyContents "Sent from shared mailbox" --output json

Reply to email (via Graph API)

The CLI has no built-in reply command. Use m365 request with the Graph API reply endpoint:

# Reply to sender only (plain text comment)
cat > /tmp/m365_reply.json << 'EOF'
{
  "comment": "Thanks, that works for me!"
}
EOF

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/messages/<message-id>/reply" \
  --method post --body @/tmp/m365_reply.json --content-type "application/json"

# Reply all
m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/messages/<message-id>/replyAll" \
  --method post --body @/tmp/m365_reply.json --content-type "application/json"

# Reply with HTML body and additional recipients
cat > /tmp/m365_reply.json << 'EOF'
{
  "message": {
    "toRecipients": [
      {"emailAddress": {"address": "extra@example.com", "name": "Extra Recipient"}}
    ]
  },
  "comment": "<p>Replying with <b>HTML</b> content.</p>"
}
EOF

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/messages/<message-id>/reply" \
  --method post --body @/tmp/m365_reply.json --content-type "application/json"

The Graph API handles threading, quoting the original message, and setting recipients automatically. Use comment for the reply text. Optionally include a message object to add/override recipients. Returns 202 Accepted with no body on success. Requires Mail.Send permission.

Move / archive messages

m365 outlook message move --id <message-id> \
  --sourceFolderName inbox --targetFolderName archive --output json

Calendar

Calendar operations use m365 request with Microsoft Graph API endpoints. For POST/PUT/PATCH requests, write the JSON body to a temp file and pass it with --body @/path/to/file.json --content-type "application/json".

List calendars

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/calendars?\$select=name,id,canEdit,isDefaultCalendar" --method get --output json

List upcoming events (calendar view)

Use calendarView for events in a date range (expands recurring events):

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/calendarView?\$select=subject,start,end,location,organizer,isAllDay&startDateTime=2026-02-17T00:00:00Z&endDateTime=2026-02-24T00:00:00Z&\$orderby=start/dateTime" --method get --output json

Get event details (with attendees)

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/events/<event-id>?\$select=subject,start,end,location,organizer,attendees,body,onlineMeeting" --method get --output json

Search events

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/events?\$filter=contains(subject,'keyword')&\$select=subject,start,end&\$top=10" --method get --output json

Create event

Write the event JSON to a temp file, then POST:

cat > /tmp/m365_event.json << 'EOF'
{
  "subject": "Meeting Title",
  "start": {"dateTime": "2026-03-01T14:00:00", "timeZone": "Europe/Berlin"},
  "end": {"dateTime": "2026-03-01T15:00:00", "timeZone": "Europe/Berlin"},
  "location": {"displayName": "Conference Room"},
  "attendees": [
    {"emailAddress": {"address": "attendee@example.com", "name": "Name"}, "type": "required"}
  ],
  "body": {"contentType": "text", "content": "Agenda: ..."}
}
EOF

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/events" \
  --method post --body @/tmp/m365_event.json --content-type "application/json" --output json

Delete event

m365 request --url "https://graph.microsoft.com/v1.0/users/<upn>/events/<event-id>" \
  --method delete

Tips

• Paginated results include @odata.nextLink. Fetch the next page by passing that URL to m365 request.
• Use --query (JMESPath) to extract specific fields: --query "[].{subject:subject,from:from.emailAddress.address}".
• For Graph API requests, use \$ to escape $ in shell.
• $top limits results: $top=5 returns at most 5 items.
• Graph API datetimes are UTC. Specify timeZone in event start/end for local times.