Postfix: status=deferred (connect ... Connection timed out) Email / SMTP Origin: Network Last updated 4 Nov 2026

Postfix: status=deferred (connect to gmail-smtp-in.l.google.com[142.250.27.26]:25: Connection timed out)

Postfix could not reach the remote mail server on port 25, so the message stays in the queue and is retried.

Exact message you may see status=deferred (connect to gmail-smtp-in.l.google.com[142.250.27.26]:25: Connection timed out)postfix/smtp status=deferred Connection timed outstatus=deferred (connect to ... Connection refused)postfix queue deferred connection timed out
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Seen on: SMTP Linux

Meaning

postfix/smtp logs the destination and reason. A timeout usually means outbound port 25 is blocked by your host or ISP (very common on cloud providers), a firewall rule, or a routing problem. Use a smarthost/relay on port 587 or 2525 instead of direct delivery.

Common causes

  • Outbound port 25 blocked by the cloud provider/ISP
  • Firewall or security group denies egress
  • Remote server down or blocking your IP
  • IPv6 route broken while Postfix prefers IPv6
  • DNS returning unreachable MX

⚡ Quick fix

  1. Test nc -vz gmail-smtp-in.l.google.com 25 from the server
  2. Configure a relayhost with port 587 and SASL credentials
  3. Force IPv4: inet_protocols = ipv4

Detailed fix by platform

Linux

  1. postqueue -p (list), postsuper -d ALL deferred (clear), and grep status=deferred /var/log/mail.log | tail

Code examples

Relay through a smarthost (main.cf)

ini
relayhost = [smtp.example.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_security_level = encrypt

How to diagnose

  1. Port — nc to port 25 succeeds?
  2. Egress — Firewall/cloud rules?
  3. IPv6 — Fails over IPv6 only?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: Network. Errors that are often confused with or caused by this one (click to open):

421 4.7.0 Try again later (rate limited) — SMTP: 421 4.7.0 Our system has detected an unusual rate of unsolicited mail originating from your IP address. Mail sent from your IP address has been temporarily rate limited (Email / SMTP)421 4.7.0 Try again l…450 4.7.1 Greylisted, please try again later — SMTP: 450 4.7.1 <user@example.com>: Recipient address rejected: Greylisted, see http://postgrey.schweikert.ch/help/example.com.html (Email / SMTP)450 4.7.1 Greylisted,…451 4.3.0 Local error in processing — SMTP: 451 4.3.0 Error: queue file write error / 451 Requested action aborted: local error in processing (Email / SMTP)451 4.3.0 Local error…554 5.4.14 Hop count exceeded - possible mail loop — SMTP: 554 5.4.14 Hop count exceeded - possible mail loop (Email / SMTP)554 5.4.14 Hop count …Outbound port 25 blocked — SMTP: telnet smtp.example.com 25 — Connection timed out (cloud provider blocks port 25) (Email / SMTP)Outbound port 25 bloc…Postfix: bind 0.0.0.0 port 25: Address already in use — Postfix: fatal: bind 0.0.0.0 port 25: Address already in use (Email / SMTP)Postfix: bind 0.0.0.0…Postfix: Host or domain name not found — Postfix: status=deferred (Host or domain name not found. Name service error for name=example.com type=A: Host not found, try again) (Email / SMTP)Postfix: Host or doma…Postfix: SASL authentication failed — Postfix: warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory (Email / SMTP)Postfix: SASL authent…Postfix: …

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