Email in Odoo drives notifications, chatter messages, sales orders, invoices, and CRM leads. If email doesn't work, you miss customer communication, invoices get stuck, and leads aren't created. It's business-critical.
Outgoing email (SMTP)
Under Settings → Technical → Email → Outgoing Mail Servers. Configure SMTP server, port (587 for TLS), username, and password. Gmail, Office 365, Amazon SES, or your own mail server. Test with the "Test Connection" button.
SPF, DKIM, and DMARC must be configured in your DNS. Without them, Odoo emails land in spam. That's not Odoo's fault; it's email infrastructure every sender needs in place.
Incoming email
Under Settings → Technical → Email → Incoming Mail Servers. IMAP or POP3. Odoo polls the server regularly (every 5 minutes by default). Incoming mail is matched against existing conversations based on message-ID and references header.
Catchall and aliases
Catchall address (e.g., catchall@your-domain.com) catches all email not matching a specific alias. Aliases: sales@your-domain.com creates a CRM lead, support@your-domain.com creates a helpdesk ticket. Configured per module.
Common problems
Email stuck in outgoing queue: check Settings → Technical → Email → Emails. Status "Exception" with error message shows what went wrong. Often: SMTP authentication failed, rate limit reached, or SPF/DKIM issues.
Odoo's cron job "Mail: Email Queue Manager" must run regularly. If scheduled actions aren't running (misconfigured cron), no emails are sent. Check under Settings → Technical → Automation → Scheduled Actions.