Without properly configured SMTP, none of these emails leave your CRM.
SMTP (Simple Mail Transfer Protocol) is the standard internet protocol for sending emails. When SuiteCRM sends a workflow notification, campaign email, or personal message from a contact record, it uses SMTP to deliver that email through a mail server to the recipient’s inbox.
Think of SMTP as the postal service for email — your CRM writes the letter (email content), hands it to the SMTP server (post office), which routes it to the recipient’s email provider for delivery.
SuiteCRM uses SMTP for all outbound email: workflow notifications (deal stage alerts, task reminders, case updates), campaign and newsletter sends (bulk email to target lists), personal emails sent from contact records by individual users, system emails (password resets, user notifications), and auto-responder emails triggered by inbound form submissions or support cases.
Without properly configured SMTP, none of these emails leave your CRM.
Every SMTP setup requires four pieces of information:
SMTP Server Address. The hostname of your email provider’s mail server. Common examples: smtp.gmail.com (Gmail/Google Workspace), smtp.office365.com (Microsoft 365), email-smtp.us-east-1.amazonaws.com (Amazon SES).
Port. The network port the SMTP server listens on. Port 587 (STARTTLS) is the modern standard — recommended for almost all providers. Port 465 (SSL/TLS) is used by some providers. Port 25 (unencrypted) should never be used in production.
Authentication. Your username (usually the full email address) and password (or App Password for Gmail, or OAuth token for modern authentication).
Encryption. TLS (Transport Layer Security) encrypts the connection between your CRM and the mail server, preventing eavesdropping. Always enable TLS or SSL — never send CRM emails unencrypted.
SMTP sends emails out. IMAP (Internet Message Access Protocol) receives emails in. SuiteCRM uses both: SMTP for outbound (sending notifications, campaigns, personal emails) and IMAP for inbound (monitoring mailboxes, auto-creating Cases from support emails, archiving correspondence).
Both must be configured for full email functionality.
“Connection refused.” Your hosting provider blocks outbound SMTP ports (common on shared hosting and AWS EC2). Solution: use port 587 or request port unblocking.
“Authentication failed.” Wrong credentials, or your email provider requires App Passwords (Gmail) or OAuth 2.0 instead of regular passwords. Google and Microsoft are deprecating basic password authentication.
Emails going to spam. Missing SPF, DKIM, and DMARC DNS records on your sending domain. These records verify that your CRM server is authorized to send email on behalf of your domain.
Emails not sending at all. The SuiteCRM Scheduler may not be running. Campaign emails and some workflow emails depend on the scheduler’s “Run Nightly Mass Email Campaigns” job being active.
For small teams (under 1,000 emails/month), your existing Gmail or Outlook account works fine. For larger volumes, dedicated SMTP services provide better deliverability and reputation management: Amazon SES (~$0.10 per 1,000 emails), SendGrid (free up to 100/day), and Mailgun (competitive pricing with analytics).
TechEsperto configures SMTP as part of every SuiteCRM implementation. Contact us for email setup help.
