Mumara uses Laravel's queue system to run heavy work in the background — sending campaigns, processing imports, generating exports, calculating statistics, parsing bounces, and handling ESP webhooks — so the web interface stays responsive. When a background job errors out and can't complete, it's recorded under Tools → Logs → Failed Jobs for review.
Jobs fail for a handful of reasons: the retry limit was exhausted (MaxAttemptsExceededException), the job timed out, PHP ran out of memory, an external service like an SMTP server or API was unavailable, the database connection dropped, or the job payload contained invalid data. For each failure the system captures the connection and queue name, the full exception message and stack trace, and the failure timestamp, so you can pinpoint exactly what went wrong.
Many failures are temporary — a brief network blip or service outage. Once you've fixed the underlying cause, you can retry the job to complete the original operation; retrying without fixing the problem just produces another failure. Delete failed jobs once they're resolved or no longer relevant (for example, a time-sensitive email that's now days old).
Worth knowing: queue workers must be running for jobs to process at all — check Cron Status if jobs aren't executing. Review failures daily rather than letting them accumulate; multiple jobs failing with similar errors usually point to an infrastructure or configuration problem, and memory failures often mean the PHP memory_limit needs raising.