AWS SES

Amazon Simple Email Service is the bulk email sending and receiving infrastructure that powers transactional email for an enormous proportion of internet applications. Launched in 2011, SES offers both an SMTP interface — for applications that speak standard email protocols — and an API endpoint for programmatic sending. The pricing model, at fractions of a cent per email for messages sent from EC2 instances, made it the default choice for transactional email at scale, displacing more expensive alternatives for the vast majority of high-volume sending use cases. SES handles sending for a huge variety of workloads: order confirmations, password resets, notifications, marketing campaigns, and event-driven alerts.

SES operates in multiple AWS regions, and the infrastructure spans both the outbound SMTP relay network that accepts messages from senders and the delivery network that routes email to receiving mail servers. The deliverability reputation of the SES sending infrastructure — managed through IP pool allocation and bounce and complaint rate monitoring — is a shared resource: senders whose messages generate high bounce or spam complaint rates can affect deliverability for other SES customers on the same sending IP pool. Dedicated IPs, available for high-volume senders, isolate reputation but add configuration and cost overhead.

When SES is degraded, the failures that applications experience depend on which layer is affected. SMTP relay failures cause application email calls to fail with connection errors before messages are even accepted into the SES queue. API send failures return error responses immediately. More insidiously, accepted messages — where SES has returned a success response — may be delayed in the SES delivery queue for hours before eventually being delivered or bounced, giving applications no visibility into the delay. Receiving failures — where SES is configured to accept inbound email for routing to S3 or Lambda — can silently drop incoming messages during queue processing degradation without returning any error to the sending party.

Outage.gg monitors AWS SES status through community reports from developers and businesses. If transactional email is not sending, API calls are failing, or delivery is significantly delayed, the live status page shows current incident data from the SES user community.