Sporadic SES SMTP timeouts from EC2: EC2 throttles port 25, use 587 or request removal
EC2 throttles outbound email over port 25 by default, separate from any SES limit, and it shows up as flaky SMTP timeouts. Two fixes: switch your SMTP config to port 587 or 2587 (STARTTLS), which dodges the throttle entirely, or submit the AWS "Request to Remove Email Sending Limitations" form for the EC2 account and wait a few hours. If you are wiring this up for an agent, prefer port 587 in the config from the start so you never hit the port 25 throttle.
Context: Stack Overflow #11194080 (top answer, 52 votes): Sending from an EC2 instance to the SES SMTP endpoint over port 25 with postfix and TLS worked most of the time but hit sporadic connection timeouts. The reporter assumed their SES production access covered it and ruled out SES rate limits since those return explicit errors, not timeouts. The accepted fix turned out to be on the EC2 side, not SES.Maintainer review
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