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Voicemail-to-Email Not Arriving

Symptom: voicemail itself works (user hears messages via *97), but emails with the .wav attachment never arrive.

Most Likely Causes

  1. SMTP relay not configured — Postfix is trying to deliver direct, getting bounced by recipient mail servers (no SPF/DKIM).
  2. SMTP credentials wrong — auth fails at the relay.
  3. Email address blank or wrong on the extension.
  4. Attachment too large — recipient mail server rejects > 10MB.
  5. Recipient mail server rate-limiting / spam-filtering the PBX's IP.
  6. Postfix queue stuck — ran out of disk, permission issue.

Diagnose

# Check if mail leaves the box:
echo "test body" | mail -s "test from PBX" you@example.com

# Watch what Postfix does:
tail -f /var/log/maillog
# Look for the test mail's status: "status=sent" / "deferred" / "bounced".

# Check the queue:
mailq

# Verify the extension's email is set:
mysql -u root asterisk -e "SELECT extension,name,email FROM users WHERE extension='<ext>';"

Fix

  • No SMTP relay configured: System Admin → Sysadmin → Email Setup → set up a relay (Gmail with app password, SendGrid, etc.). See Configure Email and DNS (Sysadmin).
  • Auth failing at relay: double-check username, password (Gmail requires App Password, not the account password), TLS port (587 typically).
  • Wrong email on extension: User Attributes → Extensions → → Voicemail → Email Address — fix it.
  • Attachment too large: in voicemail global settings, lower Max Message Length to ~3 minutes.
  • Spam-filtered: check the recipient's spam folder. Set up SPF and DKIM for the sending domain. Ask recipient to whitelist.
  • Stuck queue: postqueue -p lists stuck items; postsuper -d ALL clears (only if you don't need them).

When to Escalate

maillog shows status=sent consistently but emails never arrive — relay is delivering somewhere they don't want them. Recipient mail provider has them in spam or has blocked the relay. Contact recipient's IT.